@article {2129,
	title = {Mixing schemes in a urea-H2O system: A differential approach in solution thermodynamics},
	journal = {Journal of Physical Chemistry B},
	volume = {112},
	number = {36},
	year = {2008},
	note = {ISI Document Delivery No.: 345EVTimes Cited: 5Cited Reference Count: 29Koga, Yoshikata Miyazaki, Yuji Nagano, Yatsuhisa Inaba, Akira},
	month = {Sep},
	pages = {11341-11346},
	type = {Article},
	abstract = {The excess partial molar enthalpies of urea (UR), H-UR(E), were experimentally determined in UR-H2O at 25 degrees C. The H-UR(E) data were determined accurately and in small increments in the mole fraction of UR, X-UR, up to X-UR approximate to 0.22. Hence it was possible to evaluate one more X-UR-derivative graphically Without resorting to any fitting function, and the model-fi-ee UR-UR enthalpic interaction, H{\textquoteright}U{\textquoteright}-R-uR, was calculated. Using previous data for the excess chemical potential, mu(E)(UR), the entropy analogue, S-UR(E)-UR. was also calculated. The X-UR-dependences of both H-UR(E)-UR and S-UR(E)-UR indicate that there is a boundary at X-UR approximate to 0.09 at which the aggregation nature of urea changes. Front the results of our earlier works, we suggest that a few UR molecules aggregate at X-UR approximate to 0.09, while the integrity of H2O is retained at least up to X-UR approximate to 0.20. Together with the findings from our previous studies, we suggest that in the concentration range X-UR < 0.22, UR or its aggregate form hydrogen bonds to the H2O network, reducing the degree of fluctuation characteristic to liquid H2O. However, up to at least X-UR = 0.20 the hydrogen bond network remains intact. Above X-UR approximate to 0.22, the integrity of H2O is likely be lost. Thus, in discussing the effect of urea on H2O and in relating it to the Structure and function of biopolymers in aqueous solutions, the concentration region in question must be specified.},
	keywords = {25-DEGREES-C, AQUEOUS UREA, DYNAMICS, ENTHALPIES, H2O, LIQUID WATER, MOLECULAR-ORGANIZATION, NUCLEAR-MAGNETIC-RESONANCE, POTASSIUM, WATER-STRUCTURE},
	isbn = {1520-6106},
	url = {<Go to ISI>://000258979800023},
	author = {Koga,Yoshikata and Miyazaki, Y. and Nagano, Y. and Inaba, A.}
}
@article {1527,
	title = {A simple, catalytic H-2-hydrogenation method for the synthesis of fine chemicals; hydrogenation of protoporphyrin IX dimethyl ester},
	journal = {Tetrahedron Letters},
	volume = {47},
	number = {29},
	year = {2006},
	note = {ISI Document Delivery No.: 058XJTimes Cited: 2Cited Reference Count: 61Reboucas, Julio S. James, Brian R.},
	month = {Jul},
	pages = {5119-5122},
	type = {Article},
	abstract = {A conceptually simple H-2-hydrogenation protocol is introduced for the high-yield preparation of a natural product derivative. Protoporphyrin IX dimethyl ester is hydrogenated to the mesoporphyrin analogue in N,N-dimethylacetamide under H-2 (1 atm) at 80 degrees C within 30 min. The reaction is catalyzed by commercial RUCl3, without the need for the use of phosphine- and/or carbene-based ligands. (c) 2006 Elsevier Ltd. All rights reserved.},
	keywords = {ASYMMETRIC CATALYSIS, CARBON-MONOXIDE, COMPLEXES, HEME OXYGENASE-1, HORSERADISH-PEROXIDASE, MESOPORPHYRIN, METALLOPORPHYRINS, NUCLEAR-MAGNETIC-RESONANCE, PORPHYRIN, RUTHENIUM(II) MYOGLOBIN},
	isbn = {0040-4039},
	url = {<Go to ISI>://000238697600028},
	author = {Reboucas, J. S. and James, Brian R.}
}
@article {1296,
	title = {Dynamic C-13 NMR studies of ligand exchange in linear (d(10)) silver(I) and gold(I) and square-planar (d(8)) rhodium(I) homoleptic metal carbonyl cations in superacidic media},
	journal = {Magnetic Resonance in Chemistry},
	volume = {43},
	number = {7},
	year = {2005},
	note = {ISI Document Delivery No.: 936FUTimes Cited: 0Cited Reference Count: 21},
	month = {Jul},
	pages = {520-527},
	type = {Article},
	abstract = {The dynamic CO exchange of the monovalent metal carbonyl cations [Ag((CO)-C-13)](+), [Au((CO)-C-13)(2)](+)-Au((CO)-C-13) SO3F and [Rh((CO)-C-12)(4-x)((CO)-C-13)(x)](+) (x <= 1) in superacidic solutions was studied by variable-temperature C-13 NMR methods. The exchange rates are strongly dependent on the acidity of the solvent, the concentration of metal carbonyl cations and temperature. Whereas a suitable exchange rate of the Ag(I) system is only accessible in magic acid (HSO3F-SbF5), the more stable Au(I) and Rh(I) systems were studied in the less acidic fluorosulfuric acid. Selected solutions of Ag(I), Rh(I) and Au(I) yielded activation barriers Delta G* of 42.7, 43.5, and 56.2 kJ mol(-1) respectively. Copyright (c) 2005 John Wiley \& Sons, Ltd.},
	keywords = {C-13 NMR, CO exchange, CRYSTAL, dynamic NMR, fluorosulfuric acid, GOLD, HINDERED INTERNAL ROTATION, HSO3F-SBF5, magic acid, metal carbonyl cations, NMR, NUCLEAR-MAGNETIC-RESONANCE, rhodium, silver, UNDECAFLUORODIANTIMONATE(V), VIBRATIONAL-SPECTRA},
	isbn = {0749-1581},
	url = {<Go to ISI>://000229841700003},
	author = {von Ahsen, B. and Bach, C. and Balzer, G. and Bley, B. and Bodenbinder, M. and Hagele, G. and Willner, H. and Aubke, F.}
}
@article {1093,
	title = {Interaction of alamethicin with ether-linked phospholipid bilayers: Oriented circular dichroism, P-31 solid-state NMR, and differential scanning calorimetry studies},
	journal = {Biophysical Journal},
	volume = {89},
	number = {4},
	year = {2005},
	note = {ISI Document Delivery No.: 968FPTimes Cited: 22Cited Reference Count: 60},
	month = {Oct},
	pages = {2434-2442},
	type = {Article},
	abstract = {The arrangement of the antimicrobial peptide alamethicin was studied by oriented circular dichroism, 31 P solidstate NMR, and differential scanning calorimetry in ether- linked phospholipid bilayers composed of 1,2-O-dihexadecyl- sn-glycero3- phosphocholine ( DHPC). The measurements were performed as a function of alamethicin concentration relative to the lipid concentration, and results were compared to those reported in the literature for ester-linked phospholipid bilayers. At ambient temperature, alamethicin incorporates into the hydrophobic core of DHPC bilayers but results in more lipid disorder than observed for ester-linked 1-palmitoyl, 2-oleoyl-sn-glycero-3-phosphatidylcholine ( POPC) lipid bilayers. This orientational disorder appears to depend on lipid properties such as bilayer thickness. Moreover, the results suggest that alamethicin inserts into the hydrophobic core of the bilayers ( at high peptide concentration) for both ether- and ester-linked lipids but using a different mechanism, namely toroidal for DHPC and barrel-stave for POPC.},
	keywords = {BIOLOGICAL-MEMBRANES, CYTOCHROME-C, DIPHYTANOYL PHOSPHATIDYLCHOLINE, FUSION PEPTIDES, HYDROPHOBIC MISMATCH, LIPID-BILAYER, MOLECULAR-DYNAMICS SIMULATIONS, NUCLEAR-MAGNETIC-RESONANCE, THERMOTROPIC PHASE-BEHAVIOR, X-RAY-DIFFRACTION},
	isbn = {0006-3495},
	url = {<Go to ISI>://000232147600025},
	author = {Dave, P. C. and Billington, E. and Pan, Y. L. and Straus, S. K.}
}
@article {1069,
	title = {Molecules with large-amplitude torsional motion partially oriented in a nematic liquid crystal: Ethane and isotopomers},
	journal = {Journal of Physical Chemistry A},
	volume = {109},
	number = {48},
	year = {2005},
	note = {ISI Document Delivery No.: 990RPTimes Cited: 10Cited Reference Count: 48},
	month = {Dec},
	pages = {11027-11036},
	type = {Article},
	abstract = {An NMR study on ethane and five isotopomers dissolved in the nematic liquid crystal Merck ZLI 1132 is performed. A consistent set of dipolar and quadrupolar couplings is obtained. The dipolar couplings are corrected for harmonic vibrational effects, while the contribution from the torsional motion is incorporated classically. The corrected dipolar couplings cannot be understood in terms of a reasonable molecular structure unless effects of the reorientation-vibration interaction are taken into account. Assuming that the reorientation-vibration contributions that are known for the methyl group in methyl fluoride are transferable to ethane, excellent agreement between observed and calculated dipolar couplings is obtained on the basis of the ethane gas-phase structure. The observed and calculated deuterium quadrupolar couplings show discrepancies supporting the notion that average electric field gradients are important in liquid-crystal solvents. An important consequence of the transferability of the reorientation-vibration correlation is that in other molecules with a methyl group the same procedure as for ethane can be followed. Inclusion of this effect generally removes the need to interpret changes in observed dipolar couplings in terms of elusive chemical effects.},
	keywords = {ANISOTROPIC, ELECTRIC-FIELD GRADIENTS, ENVIRONMENTS, FORCE-FIELDS, H-2 NMR, NUCLEAR-MAGNETIC-RESONANCE, orientational order, POLYATOMIC-MOLECULES, ROTATION, SPECTRA, VIBRATIONS},
	isbn = {1089-5639},
	url = {<Go to ISI>://000233761200026},
	author = {Burnell, E. E. and de Lange, C. A. and Barnhoorn, J. B. S. and Aben, I. and Levelt, P. F.}
}
@article {1068,
	title = {NMR as a tool in the investigation of fundamental problems in ordered liquids},
	journal = {Solid State Nuclear Magnetic Resonance},
	volume = {28},
	number = {2-4},
	year = {2005},
	note = {ISI Document Delivery No.: 998NHTimes Cited: 9Cited Reference Count: 49},
	month = {Sep},
	pages = {73-90},
	type = {Article},
	abstract = {An overview is presented of modern NMR techniques and a variety of experimental and theoretical tools employed in the study of solutes dissolved in liquid crystals. The NMR techniques involve multiple quantum and spectral subtraction methods, In addition, various experimental and theoretical tools are discussed, including: the theoretical background of observed order parameters; the use of,magic mixtures{\textquoteright} to separate orientational contributions; the reorientation-vibration interaction; the use of model calculations based on size and shape of the various solutes; and the use of computer simulations. Applications to the benchmark probe molecules hydrogen, methane, ethane, and butane and their isotopomers are treated. (c) 2005 Elsevier Inc. All rights reserved.},
	keywords = {ANISOTROPIC LIQUIDS, butane, ethane, H-2 NMR, HYDROGEN, INTERNAL-ROTATION, liquid crystal, METHANE, MOLECULES, MOLEKULAR-STATISTISCHE THEORIE, MULTIPLE-QUANTUM NMR, NEMATISCHEN KRISTALLINFLUSSIGEN PHASE, NMR, NUCLEAR-MAGNETIC-RESONANCE, order parameter, orientational order, PROTON DIPOLAR COUPLINGS, SMALL CHAIN},
	isbn = {0926-2040},
	url = {<Go to ISI>://000234325100003},
	author = {Burnell, E. E. and de Lange, C. A.}
}
@article {1115,
	title = {Solid state NMR method for the determination of 3D zeolite framework/sorbate structures: H-1/Si-29 CP MAS NMR study of the high-loaded form of p-xylene in ZSM-5 and determination of the unknown structure of the low-loaded form},
	journal = {Journal of the American Chemical Society},
	volume = {127},
	number = {20},
	year = {2005},
	note = {ISI Document Delivery No.: 928AXTimes Cited: 22Cited Reference Count: 57},
	month = {May},
	pages = {7543-7558},
	type = {Article},
	abstract = {A general protocol is described for structure determinations of organic sorbate-zeolite complexes based on the selective, through-space, distance-dependent transfer of magnetization from protons in selectively deuterated organics to framework silicon nuclei. The method was developed using the known structure of the high-loaded ZSM-5/p-xylene complex containing p-xylene-d(6) or p-xylene-d(4). It was then applied to determine the unknown structure of the low-loaded ZSM-5/p-xylene complex using NMR alone. For the high-loaded complex improved data were obtained below 273 K, where slow motions and exchange processes of the p-xylene are eliminated. The general approach was validated by. the exact agreement of the experimental H-1-Si-29 CPMAS spectra obtained at a specific contact time and the complete 24-line spectra simulated using 1/T-CP vs M-2 correlations from only the six clearly resolved resonances. For the low-loaded complex the Si-29 resonances were assigned at 267 K, and variable contact time CP experiments were carried out between 243 and 173 K using the same specifically deuterated p-xylenes. All possible locations and orientations of the p-xylene guests were sampled, and those solutions that gave acceptable linear 1/T-CP vs M-2 correlations were selected. The optimum p-xylene location in this temperature range was determined to be in the channel intersection with the long molecular axis parallel to [0,1,0] (ring center fractional coordinates {-0.009, 0.250, 0.541}) with the ring plane oriented at an angle of 30 +/- 3 degrees about the crystallographic b axis. A subsequent single-crystal X-ray study confirmed this predicted structure.},
	keywords = {3-DIMENSIONAL BONDING CONNECTIVITIES, CROSS-POLARIZATION, CRYSTAL STRUCTURE-ANALYSIS, LATTICE, MAGIC-ANGLE, NATURAL-ABUNDANCE, NUCLEAR-MAGNETIC-RESONANCE, PROTON-ENHANCED NMR, SINGLE-CRYSTAL, SPINNING NMR, structures},
	isbn = {0002-7863},
	url = {<Go to ISI>://000229244600061},
	author = {Fyfe, C. A. and Diaz, A. C. and Grondey, H. and Lewis, A. R. and Forster, H.}
}
@article {1044,
	title = {NMR measurement of smectic ordering and nematic-smectic-A coupling in a liquid crystal},
	journal = {Chemical Physics Letters},
	volume = {398},
	number = {4-6},
	year = {2004},
	note = {ISI Document Delivery No.: 867OVTimes Cited: 11Cited Reference Count: 31},
	month = {Nov},
	pages = {517-521},
	type = {Article},
	abstract = {The nuclear magnetic resonance (NMR) spectra of three substituted benzenes as solutes in the liquid crystal 8CB were investigated. The orientational order of all solutes was obtained in the nematic and smectic-A phases. A change in temperature dependence of orientational ordering was observed at the nematic to smectic-A phase transition. We analyzed these results via Kobayashi-McMillan theory applied to solutes, i.e. by incorporating smectic-A layering and nematic smectic-A coupling into a mean-field orientational Hamiltonian. By fitting to experiment, we fully determined Hamiltonian prefactors. The nematic smectic coupling, determined for the first time by NMR, appears solute independent. Solute smectic-A order parameters were self-consistently determined. (C) 2004 Published by Elsevier B.V.},
	keywords = {BINARY-MIXTURES, FIELD, NUCLEAR-MAGNETIC-RESONANCE, orientational order, PHASE-TRANSITION, SHAPE, SOLUTES, TEMPERATURE-DEPENDENCE, TRICRITICAL POINT},
	isbn = {0009-2614},
	url = {<Go to ISI>://000224852800044},
	author = {Yethiraj, A. and Sun, Z. M. and Dong, R. Y. and Burnell, E. E.}
}
@article {891,
	title = {Structural basis of actin sequestration by thymosin-beta 4: implications for WH2 proteins},
	journal = {Embo Journal},
	volume = {23},
	number = {18},
	year = {2004},
	note = {ISI Document Delivery No.: 861IFTimes Cited: 48Cited Reference Count: 51},
	month = {Sep},
	pages = {3599-3608},
	type = {Article},
	abstract = {The WH2 (Wiscott - Aldridge syndrome protein homology domain 2) repeat is an actin interacting motif found in monomer sequestering and filament assembly proteins. We have stabilized the prototypical WH2 family member, thymosin-beta4 (Tbeta4), with respect to actin, by creating a hybrid between gelsolin domain 1 and the C-terminal half of Tbeta4 (G1-Tbeta4). This hybrid protein sequesters actin monomers, severs actin filaments and acts as a leaky barbed end cap. Here, we present the structure of the G1-Tbeta4: actin complex at 2Angstrom resolution. The structure reveals that Tbeta4 sequesters by capping both ends of the actin monomer, and that exchange of actin between Tb4 and profilin is mediated by a minor overlap in binding sites. The structure implies that multiple WH2 motif-containing proteins will associate longitudinally with actin filaments. Finally, we discuss the role of the WH2 motif in arp2/3 activation.},
	keywords = {actin, ARP2/3 COMPLEX, BETA-THYMOSINS, BINDING-PROTEINS, CRYSTAL-STRUCTURE, DNASE-I, F-ACTIN, MONOMERIC, NEGATIVE COOPERATIVITY, NMR-SPECTROSCOPY, NUCLEAR-MAGNETIC-RESONANCE, protein crystallography, SCAR, VCA, WASp, WH2},
	isbn = {0261-4189},
	url = {<Go to ISI>://000224409100003},
	author = {Irobi, E. and Aguda, A. H. and Larsson, M. and Guerin, C. and Yin, H. L. and Burtnick, L. D. and Blanchoin, L. and Robinson, R. C.}
}
@article {744,
	title = {Assessing the effects of time and spatial averaging in N-15 chemical shift/N-15-H-1 dipolar correlation solid state NMR experiments},
	journal = {Journal of Biomolecular Nmr},
	volume = {26},
	number = {4},
	year = {2003},
	note = {ISI Document Delivery No.: 686MATimes Cited: 30Cited Reference Count: 51},
	month = {Aug},
	pages = {283-295},
	type = {Article},
	abstract = {The effect of time and spatial averaging on N-15 chemical shift/H-1-N-15 dipolar correlation spectra, i.e., PISEMA spectra, of alpha-helical membrane peptides and proteins is investigated. Three types of motion are considered: (a) Librational motion of the peptide planes in the alpha-helix; (b) rotation of the helix about its long axis; and (c) wobble of the helix about a nominal tilt angle. A 2ns molecular dynamics simulation of helix D of bacteriorhodopsin is used to determine the effect of librational motion on the spectral parameters. For the time averaging, the rotation and wobble of this same helix are modelled by assuming either Gaussian motion about the respective angles or a uniform distribution of a given width. For the spatial averaging, regions of possible N-15 chemical shift/H-1-N-15 dipolar splittings are computed for a distribution of rotations and/or tilt angles of the helix. The computed spectra show that under certain motional modes the N-15 chemical shift/H-1-N-15 dipolar pairs for each of the residues do not form patterns which mimic helical wheel patterns. As a result, the unambiguous identification of helix tilt and helix rotation without any resonance assignments or on the basis of a single assignment may be difficult.},
	keywords = {averaging, COAT PROTEIN, GRAMICIDIN CHANNEL, ION-CHANNEL, LIPID BILAYERS, MEMBRANE-PROTEIN STRUCTURE, mobility of membrane helices, MOLECULAR-DYNAMICS SIMULATION, mosaic spread, NUCLEAR-MAGNETIC-RESONANCE, PHOSPHOLIPID-BILAYER, PISA wheels, PISEMA, SPIN-EXCHANGE, time, TRANSMEMBRANE DOMAIN},
	isbn = {0925-2738},
	url = {<Go to ISI>://000183324500001},
	author = {Straus, S. K. and Scott, W. R. P. and Watts, A.}
}
@article {611,
	title = {Influence of F content on the composition of Al-rich synthetic phlogopite: Part 1. New information on structure and phase-formation from Si-29, H-1, and F-19 MAS NMR spectroscopies},
	journal = {American Mineralogist},
	volume = {88},
	number = {1},
	year = {2003},
	note = {ISI Document Delivery No.: 635DVTimes Cited: 6Cited Reference Count: 27},
	month = {Jan},
	pages = {47-53},
	type = {Article},
	abstract = {The influence of F content on the formation and stability of Al-rich phlogopite has been investigated. Samples with varying OH/F-ratios and nominal gel compositions of K(Mg3-xAlx)(Al1+xSi3-xO10)(OH)(y) (F)(2-y) (0.0 less than or equal to x less than or equal to 0.8 and 0.5 less than or equal to y less than or equal to 1.8) were studied using Si-29, H-1, and F-19 MAS NMR spectroscopies, powder X-ray diffraction, electron-probe microanalysis, and scanning electron microscopy. The synthetic phlogopites were synthesized from sol-gels in cold-seal pressure vessels at 1073 K, 2 kbar. The main phase (phlogopite) and three other impurity phases [corundum (alpha-Al2O3), kalsilite (KAlSiO4), and potassium aluminum hexafluoride (K3AlF6.0.5H(2)O)] were clearly identified by powder X-ray diffraction and electron-probe microanalysis. For phlogopite, the unit-cell parameters a(0) and b(0) decrease whereas c(0) increases with increasing Al-content (x). The average crystal size of phlogopite is about 1-2 mum. The Si-29 MAS NMR spectra show up to four resonances at approximately -91,-87, -83, and -80ppm, which can be assigned as Q(3)(nAl) signals with n = 0 - 3. The ideal Si/Al-IV ratio calculated from the initial composition is always lower than that derived experimentally. Hydroxyl-rich compositions indicate an increased Al-content in the tetrahedral sheets, suggesting a stabilizing effect on the formation of Al-rich phlogopite. These conclusions are supported by H-1 and F-19 MAS NMR spectra. The H-1 MAS NMR spectra show a water signal at 4.7 ppm, a signal due to Mg2AlOH at 1.8 ppm, and a signal due to Mg3OH at 0.7 ppm. The F-19 MAS NMR spectra exhibit a signal for Mg2AlF at -150 ppm, one due toAlF(6) (K3AlF6.0.5H(2)O) at -157 ppm, and one for Mg3F at -174 ppm. Comparison of the H-1 and F-19 MAS NMR spectra for different Al- and F- contents reveals a non-statistical distribution of F- and OH-groups at the crystallographic sites in the octahedral sheets where F prefers sites coordinated by three Mg, and OH sites with Al in the next-nearest coordination sphere.},
	keywords = {AL-27, FLUORINE, GLASSES, GRANITES, KALSILITE, KALSIO4, NUCLEAR-MAGNETIC-RESONANCE, PETROGENESIS, SILICATE MELTS, SOLUBILITY},
	isbn = {0003-004X},
	url = {<Go to ISI>://000180383600006},
	author = {Fechtelkord, M. and Behrens, H. and Holtz, F. and Fyfe, C. A. and Groat, L. A. and Raudsepp, M.}
}
@article {770,
	title = {sigma-bonded metal carbonyl cations and their derivatives: Syntheses and structural, spectroscopic, and bonding principles},
	journal = {Organometallics},
	volume = {22},
	number = {18},
	year = {2003},
	note = {ISI Document Delivery No.: 716AGTimes Cited: 22Cited Reference Count: 150},
	month = {Sep},
	pages = {3612-3633},
	type = {Review},
	abstract = {Homoleptic sigma-bonded metal carbonyl cations (sigma-carbonyls) and their derivatives have grown in recent years into a large subgroup of mononuclear metal carbonyl complexes. They are at present formed by 17 elements, including the post transition metal mercury. Most are generated in superacids: the Lewis superacid SbF5 and the conjugate Bronsted-Lewis superacid HF-SbF5. Thermally stable salts are formed with the superacid anions [Sb2F11](-) and [SbF6](-). Many of the cations are superelectrophilic, with metals in oxidation states of +2 or +3. Three different synthetic routes are developed: reductive (A) or solvolytic carbonylations (B) and oxidative methods (C). Considerable progress has been made by replacing the Lewis superacid SbF5 as reaction medium by the conjugate Bronsted-Lewis superacid HF-SbF5. This allows reactions to proceed faster in a homogeneous phase and to produce crystalline materials. In total 27 mostly recent molecular structures have been obtained, including that of [Ir(CO)(6)] [SbF6](3)(.)4HF, the first HF solvate with one of the HF molecules coordinated in an isotridentate mode to three carbon atoms of the cation. Due to the electrophilic nature of the carbonyl carbon in fluoroantimonate salts of metal carbonyl cations, extended structures are formed via significant interionic C{\textendash}- F contacts. A new a-bonded carbonyl, (CF3)(3)BCO, which has been fully characterized, expands the existence range of metal carbonyl cations to group 13. The large amount of spectroscopic and structural information accumulated is used to present a conceptually simple bonding model.},
	keywords = {CONCENTRATED SULFURIC-ACID, DENSITY-FUNCTIONAL CALCULATION, EFFECTIVE IONIC-RADII, HSO3F-SBF5, LEWIS SUPERACID, MAS-NMR-SPECTRA, MOLECULAR-STRUCTURE, NUCLEAR-MAGNETIC-RESONANCE, VIBRATIONAL-SPECTRA, WEAKLY COORDINATING ANIONS, X-RAY},
	isbn = {0276-7333},
	url = {<Go to ISI>://000185006200002},
	author = {Willner, H. and Aubke, F.}
}
@article {560,
	title = {Insertion and removal of protons in single-crystal orthorhombic molybdenum trioxide under H2S/H-2 and O-2/N-2},
	journal = {Chemistry of Materials},
	volume = {14},
	number = {4},
	year = {2002},
	note = {ISI Document Delivery No.: 542DRTimes Cited: 13Cited Reference Count: 49},
	month = {Apr},
	pages = {1788-1796},
	type = {Article},
	abstract = {Using AFM/XRD/XPS methods, in this paper, we investigate protonation and deprotonation processes in single-crystal samples of orthorhombic molybdenum trioxide (alpha-MoO3). At low temperatures, a small part of alpha-MoO3 is changed to needlelike HxMoO3 (x approximate to 0.33) along <203> directions in a H2S/H-2 gas stream. When these elongated crystallites assemble into a maze structure, the growth of HxMoO3 is gradually ceased due to closing entrance for hydrogen. At higher temperatures, the needlelike HxMoO3 crystallites turn to a growth perpendicular to <203>, which leads to the formation of HxMoO3 blocks. It is observed that the basal plane of alpha-MoO3 is severely buckled upon the protonation. Surface sulfidation is also observed. The formed HxMoO3 or surface MOS2, however, can be readily converted back to their original-phase alpha-MoO3 in air at 350-400 degreesC. This oxidation process gives rise to a flattened (010) topography (i.e., debuckling) on which shallowly divided alpha-MoO3 surface blocks bounded with {101} planes are formed. When an alpha-MoO3 (010) plane embedded with nanocrystallites is used to create surface stress or nucleation sites, the insertion mode of hydrogen along <001> is further reconfirmed in this work. A correlation of surface/bulk phases upon various chemical reactions is addressed, and a model to summarize these changes is also proposed.},
	keywords = {BRONZES, DECOMPOSITION, GROWTH, HXMOO3, HYDROGEN, MOO3, NUCLEAR-MAGNETIC-RESONANCE, RAY PHOTOELECTRON-SPECTROSCOPY, SILICA SUPPORTS, THIN-FILMS, XPS},
	isbn = {0897-4756},
	url = {<Go to ISI>://000175028700050},
	author = {Zeng, H. C. and Xie, F. and Wong, K. C. and Mitchell, K. A. R.}
}
@article {496,
	title = {Site-specific characterization of the association of xylooligosaccharides with the CBM13 lectin-like xylan binding domain from Streptomyces lividans xylanase 10A by NMR spectroscopy},
	journal = {Biochemistry},
	volume = {41},
	number = {13},
	year = {2002},
	note = {ISI Document Delivery No.: 538ARTimes Cited: 12Cited Reference Count: 53},
	month = {Apr},
	pages = {4255-4263},
	type = {Article},
	abstract = {Endo-beta-1,4-xylanase 10A (Xyn10A) from Streptomyces lividans includes an N-terminal catalytic module and a 130-residue C-terminal family 13 carbohydrate-binding module (CBM13). This latter domain adopts a beta-trefoil structure with three potential binding sites (alpha, beta, and gamma) for a variety of small sugars, xylooligosaccharides, and xylan polymers. To investigate the role of this multivalency in carbohydrate binding, we have used NMR spectroscopy to characterize the interaction of isolated CBM13 with a series of sugars. We have assigned resonances from the main chain nuclei of CBM13 using heteronuclear NMR experiments. Analysis of N-15 NMR relaxation data using the extended model free formalism reveals that CBM13 tumbles as an oblate ellipsoid (D-\/D-perpendicular to = 0.80+/-0.02) and that its backbone is relatively rigid on the sub-nanosecond time scale. In particular, the three binding sites show no distinct patterns of increased internal mobility. Ligand-induced chemical shift changes in the H-1-N-15 HSQC spectra of CBM13 were monitored as a function of increasing concentrations Of L-arabinose, lactose, D-xylose, xylobiose, xylotetraose, and xylohexaose. Patterns of shift perturbations for well-resolved resonances demonstrate that all of these sugars associate independently with the three binding sites of CBM13. On the basis of the site-specific association constants derived from a quantitative analysis of these titration data, we show that L-arabinose, lactose, and D-xylose preferentially bind to the alpha site of CBM13, xylobiose binds equally well to all three sites, and xylotetraose and xylohexaose prefer binding to the beta site. Inspection of the crystallographic structure of CBM13 [Notenboom, V., Boraston, A. B., Williams, S. J., Kilburn, D. G., and Rose, D. R. (2002) Biochemistry 41, 4246-4254] provides a rationalization for these results.},
	keywords = {BACKBONE DYNAMICS, CELLULOMONAS-FIMI CENC, CHEMICAL-SHIFTS, CRYSTAL-STRUCTURES, E-86, IMPROVED SENSITIVITY, INSOLUBLE LIGANDS, LIGAND SPECIFICITY, NUCLEAR-MAGNETIC-RESONANCE, OLIVACEOVIRIDIS, ROTATIONAL DIFFUSION},
	isbn = {0006-2960},
	url = {<Go to ISI>://000174792300010},
	author = {Scharpf, M. and Connelly, G. P. and Lee, G. M. and Boraston, A. B. and Warren, R. A. J. and McIntosh, L. P.}
}
@article {5076,
	title = {Reaction of [P2N2]Ta=CH2(Me) with ethylene: Synthesis of [P2N2]Ta(C2H4)Et, a neutral species with a beta-agostic ethyl group in equilibrium with an alpha-agostic ethyl group ([P2N2] = PhP(CH2SiMe2NSiMe2CH2)(2)PPh)},
	journal = {Journal of the American Chemical Society},
	volume = {123},
	number = {8},
	year = {2001},
	note = {ISI Document Delivery No.: 405LXTimes Cited: 26Cited Reference Count: 65},
	month = {Feb},
	pages = {1602-1612},
	type = {Article},
	abstract = {The photolysis of [P2N2]TaMe3 ([P2N2] = PhP(CH2SiMe2NSiMe2CH2)(2)PPh) produces [P2N2]Ta=CH2(Me) as the major product. The thermally unstable methylidene complex decomposes in solution in the absence of trapping agents to unidentified products. However, in the presence of ethylene [P2N2]Ta=CH2(Me) is slowly converted to [P2N2]Ta(C2H4)Et, with [P2N2]Ta(C2H4)Me observed as a minor product. A mechanistic study suggests that the formation of [P2N2]Ta(C2H4)Et results from the trapping of [P2N2]TaEt, formed by the migratory insertion of the methylene moiety into the tantalum-methyl bond. The minor product, [P2N2]Ta(C2H4)Me, forms from the decomposition of a tantalacyclobutane resulting from the addition of ethylene to [P2N2]Ta=CH2(Me) and is accompanied by the production of an equivalent of propylene. Pure [P2N2]Ta(C2H4)Et can be synthesized by hydrogenation of [P2N2]TaMe3 in the presence of PMe3, followed by the reaction bf ethylene with the resulting trihydride. Crystallographic and NMR data indicate the presence of a beta -agostic interaction between the ethyl group and tantalum center in [P2N2]Ta(C2H4)Et. Partially deuterated analogues of [P2N2]Ta(C2H4)Et show a large isotopic perturbation of resonance for both the beta -protons and the alpha -protons of the ethyl group, indicative of an equilibrium between a beta -agostic and an a-agostic interaction for the ethyl group in solution. An EXSY spectrum demonstrates that an additional fluxional process occurs that exchanges all of the H-1 environments of the ethyl and ethylene ligands. The mechanism of this exchange is believed to involve the direct transfer of the beta -agostic hydrogen atom from the ethyl group to the ethylene ligand, via the so-called beta -hydrogen transfer process.},
	keywords = {ALKYL ALKENE, C-H, CHAIN PROPAGATION, COMPLEXES, METAL-CARBON BONDS, MIGRATORY INSERTION, MOLECULAR-STRUCTURES, NUCLEAR-MAGNETIC-RESONANCE, OLEFIN, POLYMERIZATION, RAY CRYSTAL-STRUCTURE, TRANSITION-METALS},
	isbn = {0002-7863},
	url = {<Go to ISI>://000167162100008},
	author = {Fryzuk,Michael D. and Johnson, S. A. and Rettig, S. J.}
}
@article {5199,
	title = {Structure of Cdc4p, a contractile ring protein essential for cytokinesis in Schizosaccharomyces pombe},
	journal = {Journal of Biological Chemistry},
	volume = {276},
	number = {8},
	year = {2001},
	note = {ISI Document Delivery No.: 404RUTimes Cited: 16Cited Reference Count: 49},
	month = {Feb},
	pages = {5943-5951},
	type = {Article},
	abstract = {The Schizosaccharomyces pombe Cdc4 protein is required for the formation and function of the contractile ring, presumably acting as a myosin light chain. By using NMR spectroscopy, we demonstrate that purified Cdc4p is a monomeric protein with two structurally independent domains, each exhibiting a fold reminiscent of the EF-hand class of calcium-binding proteins. Although Cdc4p has one potentially functional calcium-binding site, it does not bind calcium in vitro. Three variants of Cdc4p containing single point mutations responsible for temperature-sensitive arrest of the cell cycle at cytokinesis (Gly-19 to Glu, Gly-82 to Asp, and Gly-107 to Ser) were also characterized by NMR and circular dichroism spectroscopy. In each case, the amino acid substitution only leads to small perturbations in the conformation of the protein. Furthermore, thermal unfolding studies indicate that, like wild-type Cdc4p, the three mutant forms are all extremely stable, remaining completely folded at temperatures significantly above those causing failure of cytokinesis in intact cells. Therefore, the altered phenotype must arise directly from a disruption of the function of Cdc4p rather than indirectly through a disruption of its overall structure. Several mutant alleles of Cdc4p also show interallelic complementation in diploid cells. This phenomenon can be explained if Cdcp4 has more than one essential function or, alternatively, if two mutant proteins assemble to form a functional complex. Based on the structure of Cdc4p, possible models for interallelic complementation including interactions with partner proteins and the formation of a myosin complex with Cdc4p fulfilling the role of both an essential and regulatory light chain are proposed.},
	keywords = {BINDING PROTEINS, CALCIUM-SATURATED STATES, ESSENTIAL LIGHT-CHAIN, FISSION YEAST, MYOSIN HEAVY-CHAIN, NUCLEAR-MAGNETIC-RESONANCE, REGULATORY DOMAIN, SCALLOP MYOSIN, TARGETED DISRUPTION, TROPONIN-C},
	isbn = {0021-9258},
	url = {<Go to ISI>://000167115100072},
	author = {Slupsky, C. M. and Desautels, M. and Huebert, T. and Zhao, R. H. and Hemmingsen, S. M. and McIntosh, L. P.}
}
@article {4856,
	title = {Binding site analysis of cellulose binding domain CBDN1 from endoglucanse C of Cellulomonas fimi by site-directed mutagenesis},
	journal = {Biochemistry},
	volume = {39},
	number = {30},
	year = {2000},
	note = {ISI Document Delivery No.: 339RJTimes Cited: 17Cited Reference Count: 59},
	month = {Aug},
	pages = {8844-8852},
	type = {Article},
	abstract = {Endoglucanase C (CenC), a beta 1,4 glucanase from the soil bacterium Cellulomonas fimi, binds to amorphous cellulose via two homologous cellulose binding domains, termed CBDN1 and CBDN2. in this work, the contributions of 10 amino acids within the binding cleft of CBDN1 were evaluated by single site-directed mutations to alanine residues. Each isolated domain containing a single mutation was analyzed for binding to an insoluble amorphous preparation of cellulose, phosphoric acid swollen Avicel (PASA), and to a soluble glucopyranoside polymer, barley beta-glucan. The effect of any given mutation on CBD binding was similar for both substrates, suggesting that the mechanism of binding to soluble and insoluble substrates is the same. Tyrosines 19 and 85 were essential for tight binding by CBDN1 as their replacement by alanine results in affinity decrements of approximately 100-fold on PASA, barley beta-glucan, and soluble cellooligosaccharides. The tertiary structures of unbound Y19A and Y85A were assessed by heteronuclear single quantum coherence (HSQC) spectroscopy. These studies indicated that the structures of both mutants were perturbed but that all perturbations are very near to the site of mutation.},
	keywords = {4-GLUCANASE CENC, BETA-1, ESCHERICHIA-COLI, LIGAND-BINDING, LIMITED PROTEOLYSIS, MECHANISM, N-ACETYLGLUCOSAMINE, NUCLEAR-MAGNETIC-RESONANCE, REESEI CELLOBIOHYDROLASE-I, TRICHODERMA-REESEI, TRYPTOPHAN RESIDUES},
	isbn = {0006-2960},
	url = {<Go to ISI>://000088491500018},
	author = {Kormos, J. and Johnson, P. E. and Brun, E. and Tomme, P. and McIntosh, L. P. and Haynes, C. A. and Kilburn, D. G.}
}
@article {4842,
	title = {Hydrogen bonding and catalysis: A novel explanation for how a single amino acid substitution can change the pH optimum of a glycosidase},
	journal = {Journal of Molecular Biology},
	volume = {299},
	number = {1},
	year = {2000},
	note = {ISI Document Delivery No.: 318NCTimes Cited: 96Cited Reference Count: 58},
	month = {May},
	pages = {255-279},
	type = {Article},
	abstract = {The pH optima of family 11 xylanases are well correlated with the nature of the residue adjacent to the acid/base catalyst. In xylanases that function optimally under acidic conditions, this residue is aspartic acid, whereas it is asparagine in those that function under more alkaline conditions. Previous studies of wild-type (WT) Bacillus circulans xylanase (BCX), with an asparagine residue at position 35, demonstrated that its pH-dependent activity follows the ionization states of the nucleophile Glu78 (pK(a) 4.6) and the acid/base catalyst Glu172 (pK(a) 6.7). As predicted from sequence comparisons, substitution of this asparagine residue with an aspartic acid residue (N35D BCX) shifts its pH optimum from 5.7 to 4.6, with an similar to 20 \% increase in activity. The bell-shaped pH-activity profile of this mutant enzyme follows apparent pK(a) values of 3.5 and 5.8. Based on C-13-NMR titrations, the predominant pK(a) values of its active-site carboxyl groups are 3.7 (Asp35), 5.7 (Glu78) and 8.4 (Glu172). Thus, in contrast to the WT enzyme, the pH-activity profile of N35D BCX appears to be set by Asp35 and Glu78. Mutational, kinetic, and structural studies of N35D BCX, both in its native and covalently modified 2-fluoro-xylobiosyl glycosyl-enzyme intermediate states, reveal that the xylanase still follows a double-displacement mechanism with Glu78 serving as the nucleophile. We therefore propose that Asp35 and Glu172 function together as the general acid/base catalyst, and that N35D BCX exhibits a "reverse protonation" mechanism in which it is catalytically active when Asp35, with the lower pK(a), is protonated, while Glu78, with the higher pK(a), is deprotonated. This implies that the mutant enzyme must have an inherent catalytic efficiency at least 100-fold higher than that of the parental WT, because only similar to 1\% of its population is in the correct ionization state for catalysis at its pH optimum. The increased efficiency of N35D BCX, and by inference all "acidic" family 11 xylanases, is attributed to the formation of a short (2.7 Angstrom) hydrogen bond between Asp35 and Glu172, observed in the crystal structure of the glycosyl-enzyme intermediate of this enzyme, that will substantially stabilize the transition state for glycosyl transfer. Such a mechanism may be much more commonly employed than is generally realized, necessitating careful analysis of the pH-dependence of enzymatic catalysis. (C) 2000 Academic Press.},
	keywords = {3-DIMENSIONAL STRUCTURE, 4-BETA-XYLANASES, ACTIVE-SITE, BACILLUS-CIRCULANS XYLANASE, CYCLODEXTRIN GLYCOSYLTRANSFERASE, electrostatics, ENDO-1, GLYCOSYL-ENZYME INTERMEDIATE, ISOTOPE, MOLECULAR-WEIGHT, NMR, NUCLEAR-MAGNETIC-RESONANCE, nucleophile, PANCREATIC ALPHA-AMYLASE, pH-dependent enzyme mechanism, SHIFT, TRICHODERMA-REESEI, X-RAY CRYSTALLOGRAPHY, X-ray structure},
	isbn = {0022-2836},
	url = {<Go to ISI>://000087289400019},
	author = {Joshi, M. D. and Sidhu, G. and Pot, I. and Brayer, G. D. and Withers, S. G. and McIntosh, L. P.}
}
@article {4945,
	title = {Multiple quantum and high-resolution NMR, molecular structure, and order parameters of partially oriented ortho and meta dimethyl-, dichloro-, and chloromethylbenzenes codissolved in nematic liquid crystals},
	journal = {Journal of Magnetic Resonance},
	volume = {144},
	number = {1},
	year = {2000},
	note = {ISI Document Delivery No.: 313NCTimes Cited: 18Cited Reference Count: 62},
	month = {May},
	pages = {58-73},
	type = {Article},
	abstract = {We develop a strategy for analyzing complex nuclear magnetic resonance (NMR) spectra of several solutes codissolved in liquid-crystal phases. Spectral parameters of solutes m- or o-xylene were estimated by analyzing 2D multiple-quantum NMR spectra using a modified version of a least-squares fitting routine which adjusts chemical shifts, order parameters, structural parameters, and/or dipolar couplings independently. These estimates were used to facilitate analysis of the high-resolution spectra which contain resonances from many solutes. Calculated spectra of m- or o-xylene were subtracted from the experimental high-resolution spectra leaving resonances from the other solutes readily visible, Accurate spectral parameters of all codissolved solutes were determined from the high-resolution spectra. Order parameters and structural parameters (including vibrationally corrected parameters) of m- and o-xylene, m- and o-chlorotoluene, and m- and o-dichlorobenzene were calculated from the dipolar couplings. (C) 2000 Academic Press.},
	keywords = {ELECTRIC-DIPOLE INTERACTIONS, EXCITATION, INTERNAL-ROTATION, NUCLEAR-MAGNETIC-RESONANCE, orientational order, PHASE, POTENTIALS, SELECTIVE, SOLUTES, SOLVENTS, TRANSITIONS},
	isbn = {1090-7807},
	url = {<Go to ISI>://000087004900008},
	author = {Syvitski, R. T. and Burnell, E. E.}
}
@article {4745,
	title = {Structure and binding specificity of the second N-terminal cellulose-binding domain from Cellulomonas fimi endoglucanase C},
	journal = {Biochemistry},
	volume = {39},
	number = {10},
	year = {2000},
	note = {ISI Document Delivery No.: 294HFTimes Cited: 31Cited Reference Count: 74},
	month = {Mar},
	pages = {2445-2458},
	type = {Article},
	abstract = {The 1,4-beta-glucanase CenC from Cellulomonas fimi contains two cellulose-binding domains, CBDN1 and CBDN2, arranged in tandem at its N-terminus. These homologous CBDs are distinct in their selectivity for binding amorphous and not crystalline cellulose. Multidimensional heteronuclear nuclear magnetic resonance (NMR) spectroscopy was used to determine the tertiary structure of CBDN2 in the presence of saturating amounts of cellopentaose. A total of 1996 experimental restraints were used to calculate an ensemble of 21 final structures for the protein. CBDN2 is composed of 11 beta-strands, folded into two antiparallel beta-sheets, with a topology of a jellyroll beta-sandwich. On the basis of patterns of chemical shift perturbations accompanying the addition of cellooligosaccharides, as well as the observation of intermolecular protein-sugar NOE interactions, the cellulose-binding site of CBDN2 was identified as a cleft that lies across one face of the beta-sandwich. The thermodynamic basis for the binding of cellooligosaccharides was investigated using isothermal titration calorimetry and NMR spectroscopy. Binding is enthalpically driven and consistent with a structural model involving hydrogen bonding between the equatorial hydroxyls of the glucopyranosyl rings and polar amino acid side chains lining the CBDN2 cleft. Affinity electrophoresis was used to determine that CBDN2 also binds soluble beta-1,4-linked polymers of glucose, including hydroxyethylcellulose and beta-1,3-1,4-glucans. This study complements a previous analysis of CBDN1 [Johnson, P. E., Joshi, M. D., Tomme, P., Kilburn, D. G., and McIntosh, L. P. (1996) Biochemistry 35, 14381-14394] and demonstrates that the homologous CBDs from CenC share very similar structures and sugar binding properties.},
	keywords = {3-DIMENSIONAL SOLUTION STRUCTURE, C-13-ENRICHED PROTEINS, C-13-LABELED PROTEINS, CHEMICAL-SHIFT, DISTANCE GEOMETRY, IMPROVED SENSITIVITY, INDEX, ISOTOPICALLY-ENRICHED PROTEINS, LARGER PROTEINS, NUCLEAR-MAGNETIC-RESONANCE, SIDE-CHAIN RESONANCES},
	isbn = {0006-2960},
	url = {<Go to ISI>://000085905300003},
	author = {Brun, E. and Johnson, P. E. and Creagh, A. L. and Tomme, P. and Webster, P. and Haynes, C. A. and McIntosh, L. P.}
}
@article {4549,
	title = {Characterization of Na5P3O10 polymorphs by Na-23 MAS, Na-23 MQMAS, and P-31 MAS NMR spectroscopy},
	journal = {Inorganic Chemistry},
	volume = {38},
	number = {1},
	year = {1999},
	note = {ISI Document Delivery No.: 157MUTimes Cited: 20Cited Reference Count: 42},
	month = {Jan},
	pages = {84-92},
	type = {Article},
	abstract = {The two anhydrous polymorphs of Na5P3O10 have been characterized by Na-23 and P-31 MAS NMR spectroscopy, The Na-23 multiple-quantum (MQ) MAS NMR spectrum of the low-temperature form (phase II) displays three resonances for which the quadrupole coupling parameters and isotropic chemical shifts have been accurately determined from the MAS NMR spectra of the central transition. Thereby, discrepancies between recently reported Na-23 MQMAS spectra of this phase and the crystal structure have been clarified. The Na-23 resonances observed for the low-temperature form are assigned to the crystallographically nonequivalent Na sites in the crystal structure using point-monopole calculations of the electric-field gradient tensors. Three Na-23 resonances have also been observed for the high-temperature form (phase I), with two signals having very similar quadrupolar couplings and isotropic chemical shifts indicating similar coordination environments for the corresponding Na sites, in disagreement with the reported single-crystal structure. Point-monopole calculations of the electric-field gradient tensors based on the crystal structure fail to reproduce the experimental values. The P-31 chemical shielding anisotropies, obtained from P-31 MAS NMR spectra, show that the terminal P atoms of the P3O105- ions have a negative shielding anisotropy parameter (delta(sigma) = delta(iso) - delta(33)) in agreement with similar observations reported for diphosphates. This characteristic feature has been used in the assignment of the three P-31 resonances observed for the hexahydrate Na5P3O10. 6H(2)O.},
	keywords = {2-SPIN SYSTEMS, ANGLE-SPINNING NMR, CHEMICAL SHIELDING, CONDENSED PHOSPHATES, DIPOLAR, NUCLEAR-MAGNETIC-RESONANCE, QUADRUPOLAR NUCLEI, SODIUM TRIPHOSPHATE, SOLID-STATE, SPECTRA, TENSORS},
	isbn = {0020-1669},
	url = {<Go to ISI>://000078066900013},
	author = {Fyfe, C. A. and Altenschildesche, H. M. Z. and Skibsted, J.}
}
@article {4550,
	title = {A comparison of NMR distance determinations in the solid state by cross polarization, REDOR, and TEDOR techniques},
	journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie},
	volume = {77},
	number = {11},
	year = {1999},
	note = {ISI Document Delivery No.: 253FETimes Cited: 14Cited Reference Count: 64},
	month = {Nov},
	pages = {1984-1993},
	type = {Article},
	abstract = {Solid-state NMR distance determinations using Hartmann-Hahn cross polarization between spin-1/2 nuclei (F-19/Si-29) are reported. F-19 {\textendash}> Si-29 polarization transfer for the T-1 silicon site in the clathrasil octadecasil shows an oscillatory behaviour as a function of the contact time. These oscillations were observed for non-spinning powder samples and also for different spinning speeds at the various MAS sideband matching conditions. Three analytical functions that allow efficient nonlinear least-square regression analyses of the experimental data to determine the internuclear distances for non-spinning powder samples as well as at the +/-1 and +/-2 MAS sideband matching conditions are reported. Using these functions, a F-19-Si-29 distance of 2.53 +/- 0.04 Angstrom was determined for the T-1 silicon in octadecasil from fitting of the oscillatory behaviour. This distance is in good agreement with that known from the X-ray structure and the previous F-19/Si-29 REDOR and TEDOR distance measurements. The advantages and limits of the different dipolar-based NMR techniques for heteronuclear distance determinations are examined and discussed.},
	keywords = {ANGLE-SPINNING NMR, cross polarization (CP), DISTANCE, distances F-19-Si-29, HELICAL PEPTIDE, HETERONUCLEAR DIPOLAR, interactions, INTERATOMIC, LOCK, NMR distance measurements, NUCLEAR-MAGNETIC-RESONANCE, octadecasil, PROTON-ENHANCED NMR, REDOR, ROTATIONAL-ECHO, SEQUENCES, SPIN-1/2 NUCLEI, TEDOR, TRANSIENT OSCILLATIONS},
	isbn = {0008-4042},
	url = {<Go to ISI>://000083545300032},
	author = {Fyfe, C. A. and Lewis, A. R. and Chezeau, J. M.}
}
@article {4385,
	title = {(13)CPMAS-NMR spectroscopy and chemical analysis of coarse woody debris in coastal forests of Vancouver Island},
	journal = {Forest Ecology and Management},
	volume = {111},
	number = {1},
	year = {1998},
	note = {ISI Document Delivery No.: 137DZTimes Cited: 46Cited Reference Count: 52},
	month = {Nov},
	pages = {51-68},
	type = {Article},
	abstract = {The coastal forests of British Columbia have large accumulations of coarse woody debris, and information on this pool is considered essential in developing sustainable management practices. We characterized coarse woody debris (7-12 and >12 cm diameter) in forest chronosequences of four age classes located on the eastern and western sides of Vancouver Island. For three species (Douglas-fir (Pseudotsuga menziesii (Mirb.) France), western hemlock (Tsuga heterophylla (Raf.) Sarg), western red cedar (Thuja plicata Donn.)) and unidentified samples, increases in decay class (I to V, assigned in the field) were associated with decreasing density, and small increases in concentrations of C, N, and P. Sulfur concentrations (0.6-2.4 g/kg) were higher than those found elsewhere for wood and did not show any significant changes with decay class. C-13 nuclear magnetic resonance spectroscopy with cross polarization and magic-angle spinning (C-13-CPMAS-NMR) was used to analyze organic components in a subset of samples >12 cm. Logs up to decay class III generally showed little change in composition or a slight increase in polysaccharide C. After this, polysaccharide was lost more quickly and logs of decay class V were composed almost entirely of lignin, a pattern consistent with decay by brown-rot fungi. However, two samples of western red cedar decay class III and IV showed accumulation of polysaccharide, the pattern expected from white-rot fungi. The results of the density, chemical and NMR analysis indicate that for management purposes, a system with fewer decay classes would suffice. (C) 1998 Elsevier Science B.V.},
	keywords = {BRITISH-COLUMBIA, brown-rot, chronosequence, COLORADO BLUE SPRUCE, cross polarization, CUO OXIDATION, DECOMPOSITION, DOUGLAS-FIR FORESTS, LIGNIN, NUCLEAR-MAGNETIC-RESONANCE, NUTRIENT CONTENT, SOLID-STATE NMR, SULFUR, WESTERN OREGON, white-rot, WHITE-ROT DECAY},
	isbn = {0378-1127},
	url = {<Go to ISI>://000076900700005},
	author = {Preston, C. M. and Trofymow, J. A. and Niu, J. and Fyfe, C. A.}
}
@article {4301,
	title = {Calcium binding by the N-terminal cellulose-binding domain from Cellulomonas fimi beta-1,4-glucanase CenC},
	journal = {Biochemistry},
	volume = {37},
	number = {37},
	year = {1998},
	note = {ISI Document Delivery No.: 125NRTimes Cited: 16Cited Reference Count: 33},
	month = {Sep},
	pages = {12772-12781},
	type = {Article},
	abstract = {The interaction of the N-terminal cellulose-binding domain, CBDN1, from Cellulomonas fimi beta-1,4-glucanase CenC with calcium was investigated using NMR spectroscopy and calorimetry. CBDN1 binds a single calcium ion with an equilibrium association constant of approximately 10(5) M-1 at 35 degrees C and pH 6.0. Binding is exothermic (-42 +/- 2 kJ mol(-1)) under these conditions and is accompanied by a small negative change in heat capacity (Delta C-p = -0.41 +/- 0.16 kJ mol(-1) K-1). From an NMR line shape analysis, the rate constants for calcium association and dissociation were found to be (5 +/- 7) x 10(7) s(-1) M-1 and (4.5 +/- 0.6) x 10(2) s(-1), respectively. The rapid association kinetics indicate that the calcium-binding site on CBDN1 is accessible and, to the first approximation, preformed. Based on patterns of chemical shift perturbations, and structural comparisons with the Bacillus sp. 1,3-1,4-beta-glucanases, the backbone carbonyl oxygens of Thr8, Gly30, and Asp 142 and a side chain carboxyl oxygen of Asp 142 are postulated to form the calcium-binding site of CBDN1. Consistent with the calcium-independent affinity of CBDN1 for cellopentaose, this exposed site is located on the face of CBDN1 opposite to that forming the oligosaccharide-binding cleft. The midpoint denaturation temperature of CBDN1 is increased by approximately 8 degrees C at pH 6.0 in the presence of saturating amounts of calcium, confirming that metal ion binding is thermodynamically linked to native-state stability.},
	keywords = {4-GLUCANOHYDROLASE, AFFINITY, CA2+, CRYSTAL-STRUCTURE, GLUCANASES, NUCLEAR-MAGNETIC-RESONANCE, RESOLUTION, SPECTROSCOPY, THERMODYNAMICS, THERMOSTABILITY},
	isbn = {0006-2960},
	url = {<Go to ISI>://000076244100011},
	author = {Johnson, P. E. and Creagh, A. L. and Brun, E. and Joe, K. and Tomme, P. and Haynes, C. A. and McIntosh, L. P.}
}
@article {4313,
	title = {Unfolding of proteins monitored by electrospray ionization mass spectrometry: A comparison of positive and negative ion modes},
	journal = {Journal of the American Society for Mass Spectrometry},
	volume = {9},
	number = {12},
	year = {1998},
	note = {ISI Document Delivery No.: 141FPTimes Cited: 72Cited Reference Count: 56},
	month = {Dec},
	pages = {1248-1254},
	type = {Article},
	abstract = {Electrospray ionization (ESI) mass spectrometry (MS) in both the positive and negative ion mode has been used to study protein unfolding transitions of lysozyme, cytochrome c (cyt c), and ubiquitin in solution. As expected, ESI of unfolded lysozyme leads to the formation of substantially higher charge states than the tightly folded protein in both modes of operation. Surprisingly, the acid-induced unfolding of cyt c as well as the acid and the base-induced unfolding of ubiquitin show different behavior: In these three cases protein unfolding only leads to marginal changes in the negative ion charge state distributions, whereas in the positive ion mode pronounced shifts to higher charge states are observed. This shows that ESI MS in the negative ion mode as a method for probing conformational changes of proteins in solution should be treated with caution. The data presented in this work provide further evidence that the conformation of a protein in solution not its charge state is the predominant factor for determining the ESI charge slate distribution in the positive ion mode. Furthermore, these data support the hypothesis of a recent study (Konermann and Douglas, Biochemistry 1997, 36, 12296-12302) which suggested that ESI in the positive ion mode is not sensitive to changes in the secondary structure of proteins but only to changes in the tertiary structure. (C) 1998 American Society for Mass Spectrometry.},
	keywords = {A-STATE, BINDING, CIRCULAR-DICHROISM, CYTOCHROME-C, HYDROGEN-DEUTERIUM EXCHANGE, INDUCED CONFORMATIONAL-CHANGES, MYOGLOBIN, NUCLEAR-MAGNETIC-RESONANCE, SITES, SPECTRA, UBIQUITIN},
	isbn = {1044-0305},
	url = {<Go to ISI>://000077132600002},
	author = {Konermann, L. and Douglas, D. J.}
}
@article {4020,
	title = {Complete measurement of the pK(a) values of the carboxyl and imidazole groups in Bacillus circulans xylanase},
	journal = {Protein Science},
	volume = {6},
	number = {12},
	year = {1997},
	note = {ISI Document Delivery No.: YK912Times Cited: 44Cited Reference Count: 29},
	month = {Dec},
	pages = {2667-2670},
	type = {Article},
	abstract = {Electrostatic interactions in proteins can be dissected experimentally by determining the pK(a), values of their constituent ionizable amino acids. To complement previous studies of the glutamic acid and histidine residues in Bacillus circulans xylanase (BCX), we have used NMR methods to measure the pK(a)s of the seven aspartic acids and the C-terminus of this protein. The pK(a)s of these carboxyls are all less than the corresponding values observed with random coil polypeptides, indicating that their ionization contributes favorably to the stability of the folded enzyme. In general, the aspartic acids with the most reduced pK(a)s are those with limited exposure to the solvent and a high degree of conservation among homologous xylanases. Most dramatically, Asp 53 and Asp 101 have pK(a)s < 2 and thus remain deprotonated in native BCX under all conditions examined. Asp 83 is completely buried, forming a strong salt bridge with Arg 136. In contrast, Asp 101 is located on the surface of the protein, stabilized in the deprotonated form by an extensive network of hydrogen bonds involving an internal water molecule and the neutral side-chain and main-chain atoms of Ser 100 and Thr 145. These data provide a complete experimental database for theoretical studies of the ionization behavior of BCX under acidic conditions.},
	keywords = {aspartic acid, electrostatics, FAMILIES, NMR, NMR ASSIGNMENTS, NUCLEAR-MAGNETIC-RESONANCE, PK(A), PROTEINS, RESIDUES, SHIFTS, titration, XYLANASE},
	isbn = {0961-8368},
	url = {<Go to ISI>://A1997YK91200024},
	author = {Joshi, M. D. and Hedberg, A. and McIntosh, L. P.}
}
@article {3956,
	title = {High-resolution NMR structure and backbone dynamics of the Bacillus subtilis response regulator, SpoOF: Implications for phosphorylation and molecular recognition},
	journal = {Biochemistry},
	volume = {36},
	number = {33},
	year = {1997},
	note = {ISI Document Delivery No.: XR735Times Cited: 45Cited Reference Count: 78},
	month = {Aug},
	pages = {10015-10025},
	type = {Article},
	abstract = {NMR has been employed for structural and dynamic studies of the bacterial response regulator, SpoOF. This 124-residue protein is an essential component of the sporulation phosphorelay signal transduction pathway in Bacillus subtilis. Three-dimensional H-1, N-15, and C-13 experiments have been used to obtain full side chain assignments and the 1511 distance, 121 dihedral angle, and 80 hydrogen bonding restraints required for generating a family of structures (14 restraints per residue). The structures give a well-defined (alpha/beta)(5) fold for residues 4-120 with average rms deviations of 0.59 Angstrom for backbone heavy atoms and 1.02 Angstrom for all heavy atoms. Analyses of backbone N-15 relaxation measurements demonstrate relative rigidity in most regions of regular secondary structure with a generalized order parameter (S-2) Of 0.9 +/- 0.05 and a rotational correlation time (tau(m)) of 7.0 +/- 0.5 ns, Loop regions near the site of phosphorylation have higher than average rms deviation values and T-1/T-2 ratios suggesting significant internal motion or chemical exchange at these sites, Additionally, multiple conformers are observed for the beta 4-alpha 4 loop and beta-strand 5 region, These conformers may be related to structural changes associated with phosphorylation and also indicative of the propensity this recognition surface has for differential protein interactions. Comparison of SpoOF structural features to those of other response regulators reveals subtle differences in the orientations of secondary structure in the putative recognition surfaces and the relative charge distribution of residues surrounding the site of phosphorylation, These may be important in providing specificity for protein-protein interactions and for determining the lifetimes of the phosphorylated state.},
	keywords = {3-DIMENSIONAL STRUCTURE, BACTERIAL CHEMOTAXIS, C-13 MAGNETIZATION, C-13-ENRICHED PROTEINS, C-13-LABELED PROTEINS, ESCHERICHIA-COLI, MAGNESIUM-BINDING, NUCLEAR-MAGNETIC-RESONANCE, PROTEIN SECONDARY STRUCTURE, SIGNAL-TRANSDUCTION},
	isbn = {0006-2960},
	url = {<Go to ISI>://A1997XR73500007},
	author = {Feher, V. A. and Zapf, J. W. and Hoch, J. A. and Whiteley, J. M. and McIntosh, L. P. and Rance, M. and Skelton, N. J. and Dahlquist, F. W. and Cavanah, J.}
}
@article {3750,
	title = {Highly symmetric group 13 metal-phosphinato complexes: Multinuclear NMR (Al-27, P-31, Ga-71) determination of stability constants at low pH},
	journal = {Journal of the American Chemical Society},
	volume = {118},
	number = {43},
	year = {1996},
	note = {ISI Document Delivery No.: VQ089Times Cited: 12Cited Reference Count: 56},
	month = {Oct},
	pages = {10446-10456},
	type = {Article},
	abstract = {{An N4O3 tripodal tren-based (aminomethylene)phosphinato ligand tris(4-(phenylphosphinato)-3-methyl-3-azabutyl)amine (H(3)ppma) has been synthesized, and its complexation properties with the group 13 metals Al, Ga. and In have been investigated. The molecular structure of the indium complex [In(H(3)ppma)(2)](NO3)(3) . 3H(2)O (C60H96InN11O24P6) has been solved by X-ray methods; the complex crystallizes in the trigonal space group R(3) over barc$, with a = 18.984(3) Angstrom},
	keywords = {ACID, AL(III), aluminum, AMINE PHENOL LIGANDS, AQUEOUS-SOLUTION, COMPLEXES, gallium, IONS, LANTHANIDE(III), NUCLEAR-MAGNETIC-RESONANCE, PHOSPHONODIPEPTIDES},
	isbn = {0002-7863},
	url = {<Go to ISI>://A1996VQ08900015},
	author = {Lowe, M. P. and Rettig, S. J. and Orvig, Chris}
}
@article {3708,
	title = {Interaction of soluble cellooligosaccharides with the N-terminal cellulose-binding domain of Cellulomonas fimi CenC .2. NMR and ultraviolet absorption spectroscopy},
	journal = {Biochemistry},
	volume = {35},
	number = {44},
	year = {1996},
	note = {ISI Document Delivery No.: VR098Times Cited: 68Cited Reference Count: 46},
	month = {Nov},
	pages = {13895-13906},
	type = {Article},
	abstract = {The N-terminal cellulose-binding domain (CBDN1) from Cellulomonas fimi beta-1,4-glucanase CenC binds amorphous but not crystalline cellulose. To investigate the structural and thermodynamic bases of cellulose binding, NMR and difference ultraviolet absorbance spectroscopy were used in parallel with calorimetry (Tomme, P., Creagh, A. L., Kilburn, D. G., \& Haynes, C. A., (1996) Biochemistry 35, 13885-13894] to characterize the interaction of soluble cellooligosaccharides with CBDN1 Association constants, determined from the dependence of the amide H-1 and N-15 chemical shifts of CBDN1 upon added sugar, increase from 180 +/- 60 M(-1) for cellotriose to 4 200 +/- 720 M(-1) for cellotetraose, 34 000 +/- 7 600 M(-1) for cellopentaose, and an estimate of 50 000 M(-1) for cellohexaose. This implies that the CBDN1 cellulose-binding site spans approximately five glucosyl units, On the basis of the observed patterns of amide chemical shift changes, the cellooligosaccharides bind along a five-stranded beta-sheet that forms a concave face of the jelly-roll beta-sandwich structure of CBDN1. This beta-sheet contains a strip of hydrophobic side chains flanked on both sides by polar residues, NMR and difference ultraviolet absorbance measurements also demonstrate that tyrosine, but not tryptophan, side chains may be involved in oligosaccharide binding. These results lead to a model in which CBDN1 interacts with soluble cellooligosaccharides and, by inference, with single polysaccharide chains in regions of amorphous cellulose, primarily through hydrogen bonding to the equatorial hydroxyl groups of the pyranose rings. Van der against the apolar side chains may augment binding. CBDN1 stands in marked contrast to previously characterized CBDs that absorb to crystalline cellulose via a flat binding surface dominated by exposed aromatic rings.},
	keywords = {BACKBONE H-1, CHEMICAL-SHIFTS, ESCHERICHIA-COLI, EXPRESSION, HIGH-LEVEL, NUCLEAR-MAGNETIC-RESONANCE, PROTEIN, REESEI CELLOBIOHYDROLASE-I, SEQUENCE, TRICHODERMA-REESEI, TRYPTOPHAN RESIDUES},
	isbn = {0006-2960},
	url = {<Go to ISI>://A1996VR09800005},
	author = {Johnson, P. E. and Tomme, P. and Joshi, M. D. and McIntosh, L. P.}
}
@article {3762,
	title = {The pK(a) of the general acid/base carboxyl group of a glycosidase cycles during catalysis: A C-13-NMR study of Bacillus circuluns xylanase},
	journal = {Biochemistry},
	volume = {35},
	number = {31},
	year = {1996},
	note = {ISI Document Delivery No.: VB211Times Cited: 149Cited Reference Count: 43},
	month = {Aug},
	pages = {9958-9966},
	type = {Article},
	abstract = {The 20 kDa xylanase from Bacillus circulans carries out hydrolysis of xylan via a two-step mechanism involving a covalent glycosyl-enzyme intermediate. In this double-displacement reaction, Glu78 functions as a nucleophile to form the intermediate, while Glu172 acts as a general acid catalyst during glycosylation, protonating the departing aglycone, and then as a general base during deglycosylation, deprotonating the attacking water, The dual role of Glu172 places specific demands upon its ionization states and hence pK(a) values. C-13-NMR titrations of xylanase, labeled with [delta-C-13]glutamic acid, have revealed pK(a) values of 4.6 and 6.7 for Glu78 and Glu172, respectively. These agree well with the apparent pK(a) values obtained from a study of the pH dependence of k(cat)/K-m and demonstrate that, at the enzyme{\textquoteright}s pH optimum of 5.7, the nucleophile Glu78 is deprotonated and the general acid Glu172 initially protonated. Remarkably, the pK(a) for Glu172 drops to 4.2 in a trapped covalent glycosyl-enzyme intermediate, formed by reaction with 2{\textquoteright},4{\textquoteright}-dinitrophenyl 2-deoxy-2-fluoro-beta-xylobioside [Miao et al. (1994) Biochemistry 33, 7027-7032], A similar pK(a) is measured for Glu172 when a glutamine is present at position 78. This large decrease in pK(a) of similar to 2.5 units is consistent with the role of Glu172 as a general base catalyst in the deglycosylation step and appears to be a consequence of both reduced electrostatic repulsion due to neutralization of Glu78 and a conformational change in the protein. Such {\textquoteright}{\textquoteright}pK(a) cycling{\textquoteright}{\textquoteright} during catalysis is likely to be a common phenomenon in glycosidases.},
	keywords = {ACTIVE-SITE RESIDUES, AMINO-ACIDS, beta-glucosidase, ELECTROSTATIC INTERACTIONS, ESCHERICHIA-COLI, IDENTIFICATION, LYSOZYME, MECHANISMS, NUCLEAR-MAGNETIC-RESONANCE, PROTEINS},
	isbn = {0006-2960},
	url = {<Go to ISI>://A1996VB21100003},
	author = {McIntosh, L. P. and Hand, G. and Johnson, P. E. and Joshi, M. D. and Korner, M. and Plesniak, L. A. and Ziser, L. and Wakarchuk, W. W. and Withers, S. G.}
}
@article {3621,
	title = {Probing the role of tryptophan residues in a cellulose-binding domain by chemical modification},
	journal = {Protein Science},
	volume = {5},
	number = {11},
	year = {1996},
	note = {ISI Document Delivery No.: VQ786Times Cited: 41Cited Reference Count: 34},
	month = {Nov},
	pages = {2311-2318},
	type = {Article},
	abstract = {The cellulose-binding domain (CBDCex) of the mixed function glucanase-xylanase Cex from Cellulomonas fimi contains five tryptophans, two of which are located within the p-barrel structure and three exposed on the surface (Xu GY et al., 1995, Biochemistry 34:6993-7009). Although all five tryptophans can be oxidized by N-bromosuccinimide (NBS), stopped-flow measurements show that three tryptophans react faster than the other two. NMR analysis during the titration of CBDCex with NBS shows that the tryptophans on the surface of the protein are fully oxidized before there is significant reaction with the two buried tryptophans. Additionally, modification of the exposed tryptophans does not affect the conformation of the backbone of CBDCex, whereas complete oxidation of all five tryptophans denatures the polypeptide. The modification of the equivalent of one and two tryptophans by NBS reduces binding of CBDCex to cellulose by 70\% and 90\%, respectively. This confirms the direct role of the exposed aromatic residues in the binding of CBDCex to cellulose. Although adsorption to cellulose does afford some protection against NBS, as evidenced by the increased quantity of NBS required to oxidize all of the tryptophan residues, the polypeptide can still be oxidized completely when adsorbed. This suggests that, whereas the binding appears to be irreversible overall [Ong E et al., 1989, Bio/Technology 7:604-607], each of the exposed tryptophans interacts reversibly with cellulose.},
	keywords = {absorbance spectroscopy, ACTIVE-SITE, CELLOBIOHYDROLASE-I, cellulose-binding, ENDOGLUCANASE, ESCHERICHIA-COLI, FIMI, fluorescence spectroscopy, N-bromosuccinimide, NMR, NUCLEAR-MAGNETIC-RESONANCE, SCHIZOPHYLLUM-COMMUNE, SPECTROSCOPY, TRICHODERMA-REESEI, XYLANASE-A},
	isbn = {0961-8368},
	url = {<Go to ISI>://A1996VQ78600017},
	author = {Bray, M. R. and Johnson, P. E. and Gilkes, N. R. and McIntosh, L. P. and Kilburn, D. G. and Warren, R. A. J.}
}
@article {3800,
	title = {Secondary structure and NMR assignments of Bacillus circulans xylanase},
	journal = {Protein Science},
	volume = {5},
	number = {6},
	year = {1996},
	note = {ISI Document Delivery No.: UP617Times Cited: 23Cited Reference Count: 74},
	month = {Jun},
	pages = {1118-1135},
	type = {Article},
	abstract = {Bacillus circulans xylanase (BCX) is a member of the family of low molecular weight endo-beta-(1,4)-xylanases. The main-chain H-1, C-13, and N-15 resonances of this 20.4-kDa enzyme were assigned using heteronuclear NMR experiments recorded on a combination of selectively and uniformly labeled protein samples. Using chemical shift, NOE, J coupling, and amide hydrogen exchange information, 14 beta-strands, arranged in a network of three beta-sheets, and a single cy-helix were identified in BCX. The NMR-derived secondary structure and beta-sheet topology agree closely with that observed in the crystal structure of this protein. The H-N of Ile 118 has a strongly upfield-shifted resonance at 4.03 ppm, indicative of a potential amide-aromatic hydrogen bond to the indole ring of Trp 71. This interaction, which is conserved in all low molecular weight xylanases of known structure, may play an important role in establishing the active site conformation of these enzymes. Following hen egg white and bacteriophage T4 lysozymes, B. circulans xylanase represents the third family of beta-glycanases for which extensive NMR assignments have been reported. These assignments provide the background for detailed studies of the mechanism of carbohydrate recognition and hydrolysis by this bacterial xylanase.},
	keywords = {amide-aromatic hydrogen bond, AMINO-ACID, ASSIGNMENTS, BACKBONE AMIDE, beta-glycanase, C-13-LABELED PROTEINS, C-ALPHA, chemical shift index, CHEMICAL-SHIFTS, COUPLING-CONSTANTS, LARGER PROTEINS, NMR, NUCLEAR-MAGNETIC-RESONANCE, SECONDARY STRUCTURE, SIDE-CHAIN RESONANCES, SOLVENT, SUPPRESSION, XYLANASE},
	isbn = {0961-8368},
	url = {<Go to ISI>://A1996UP61700014},
	author = {Plesniak, L. A. and Wakarchuk, W. W. and McIntosh, L. P.}
}
@article {3029,
	title = {MICROMORPHOLOGICAL AND C-13 NMR CHARACTERIZATION OF A HUMIC, LIGNIC, AND HISTIC FOLISOL FROM BRITISH-COLUMBIA},
	journal = {Canadian Journal of Soil Science},
	volume = {74},
	number = {1},
	year = {1994},
	note = {ISI Document Delivery No.: NG042Times Cited: 9Cited Reference Count: 39},
	month = {Feb},
	pages = {1-15},
	type = {Article},
	abstract = {The thick folic (mainly upland forest) materials (> 40 cm of accumulated organic material) that occur in the Coastal Western Hemlock Biogeoclimatic Zone in British Columbia have not been described with regard to the spatial interrelationships of the soil constituents in context with the chemical composition of the different horizons. Micromorphological assessment and solid-state C-13 NMR were used to characterize the accumulated folic materials from a Lignic Folisol (northern Vancouver Island), Histic Folisol (Prince Rupert, BC) and a Humic Folisol (Queen Charlotte Islands, BC). Micromorphology provided information on the spatial relationships of the soil constituents and C-13 NMR provided data on the chemical components of the folic materials. Soil faunal activity, primarily from mites, was the dominant soil-forming process observed in the organic horizons of the Folisols, being especially prominent in the Lignic Folisol with the breakdown of woody materials. Solid state C-13 CPMAS NMR spectra facilitated distinguishing three main types of horizons: (1) Horizons derived from accumulated residues (L, Fr, and Hr) showing higher carbohydrate-like C and O-alkyl C values and lower total aromatics; (2) Horizons with advanced decomposition (Hr2, Oh1, and Hd) which were higher in alkyl C; and (3) Horizons derived from ligneous material (Fw and Hdw) where carbohydrate-like C was less than total aromatic C. Implications for adequate nutrient content and forest growth were inferred from the observed micromorphology and chemical composition of the folic materials.},
	keywords = {C-13 NMR, CHEMICAL-COMPOSITION, DECOMPOSITION, FAUNAL ACTIVITY, FOLISOL, FOREST SOILS, IONIZATION MASS-SPECTROMETRY, IR, LITTER, MICROMORPHOLOGY, NITROGEN, NUCLEAR-MAGNETIC-RESONANCE, ORGANIC-MATTER, SPECTROSCOPY},
	isbn = {0008-4271},
	url = {<Go to ISI>://A1994NG04200001},
	author = {Fox, C. A. and Preston, C. M. and Fyfe, C. A.}
}
