@article {2546,
	title = {Ca2+ binding by domain 2 plays a critical role in the activation and stabilization of gelsolin},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {106},
	number = {33},
	year = {2009},
	note = {ISI Document Delivery No.: 484WETimes Cited: 5Cited Reference Count: 30Nag, Shalini Ma, Qing Wang, Hui Chumnarnsilpa, Sakesit Lee, Wei Lin Larsson, Marten Kannan, Balakrishnan Hernandez-Valladarez, Maria Burtnick, Leslie D. Robinson, Robert C.},
	month = {Aug},
	pages = {13713-13718},
	type = {Article},
	abstract = {Gelsolin consists of six homologous domains (G1-G6), each containing a conserved Ca-binding site. Occupation of a subset of these sites enables gelsolin to sever and cap actin filaments in a Ca-dependent manner. Here, we present the structures of Ca-free human gelsolin and of Ca-bound human G1-G3 in a complex with actin. These structures closely resemble those determined previously for equine gelsolin. However, the G2 Ca-binding site is occupied in the human G1-G3/actin structure, whereas it is vacant in the equine version. In-depth comparison of the Ca-free and Ca-activated, actin-bound human gelsolin structures suggests G2 and G6 to be cooperative in binding Ca2+ and responsible for opening the G2-G6 latch to expose the F-actin-binding site on G2. Mutational analysis of the G2 and G6 Ca-binding sites demonstrates their interdependence in maintaining the compact structure in the absence of calcium. Examination of Ca binding by G2 in human G1-G3/actin reveals that the Ca2+ locks the G2-G3 interface. Thermal denaturation studies of G2-G3 indicate that Ca binding stabilizes this fragment, driving it into the active conformation. The G2 Ca-binding site is mutated in gelsolin from familial amyloidosis (Finnish-type) patients. This disease initially proceeds through protease cleavage of G2, ultimately to produce a fragment that forms amyloid fibrils. The data presented here support a mechanism whereby the loss of Ca binding by G2 prolongs the lifetime of partially activated, intermediate conformations in which the protease cleavage site is exposed.},
	keywords = {actin, AMYLOIDOGENESIS, biosynthesis, calcium, calcium activated, calcium dependent, FAMILIAL AMYLOIDOSIS, IDENTIFICATION, PLASMA GELSOLIN, PROTEIN, SITE, TERMINAL HALF, TIRF},
	isbn = {0027-8424},
	url = {<Go to ISI>://000269078700018},
	author = {Nag, S. and Ma, Q. and Wang, H. and Chumnarnsilpa, S. and Lee, W. L. and Larsson, M. and Kannan, B. and Hernandez-Valladarez, M. and Burtnick, L. D. and Robinson, R. C.}
}
@article {2525,
	title = {Detection and assignment of phosphoserine and phosphothreonine residues by C-13-P-31 spin-echo difference NMR spectroscopy},
	journal = {Journal of Biomolecular Nmr},
	volume = {43},
	number = {1},
	year = {2009},
	note = {ISI Document Delivery No.: 379QKTimes Cited: 0Cited Reference Count: 31McIntosh, Lawrence P. Kang, Hyun-Seo Okon, Mark Nelson, Mary L. Graves, Barbara J. Brutscher, Bernhard},
	month = {Jan},
	pages = {31-37},
	type = {Article},
	abstract = {A simple NMR method is presented for the identification and assignment of phosphorylated serine and threonine residues in C-13- or C-13/N-15-labeled proteins. By exploiting modest (similar to 5 Hz) 2- and 3-bond C-13-P-31 scalar couplings, the aliphatic H-1-C-13 signals from phosphoserines and phosphothreonines can be detected selectively in a P-31 spin-echo difference constant time H-1-C-13 HSQC spectrum. Inclusion of the same P-31 spin-echo element within the C-13 frequency editing period of an intraHNCA or HN(CO)CA experiment allows identification of the amide H-1(N) and N-15 signals of residues (i) for which C-13(alpha)(i) or C-13(alpha)(i - 1), respectively, are coupled to a phosphate. Furthermore, P-31 resonance assignments can be obtained by applying selective low power cw P-31 decoupling during the spin-echo period. The approach is demonstrated using a PNT domain containing fragment of the transcription factor Ets-1, phosphorylated in vitro at Thr38 and Ser41 with the MAP kinase ERK2.},
	keywords = {ASSIGNMENT, CENTER-DOT-OP, CONSTANT-TIME, Ets-1, MAP kinase, NUCLEIC-ACIDS, OP HYDROGEN-BONDS, P-31-C-13 scalar coupling, Phosphoprotein, PHOSPHORYLATION, POINTED DOMAIN, PROTEIN, QUANTITATIVE J-CORRELATION, RESONANCE, SCALAR COUPLINGS, TRANSCRIPTION FACTOR},
	isbn = {0925-2738},
	url = {<Go to ISI>://000261411100004},
	author = {McIntosh, L. P. and Kang, H. S. and Okon, M. and Nelson, M. L. and Graves, B. J. and Brutscher, B.}
}
@article {2561,
	title = {Functional Cell-Based Screening and Saturation Transfer Double-Difference NMR Have Identified Haplosamate A as a Cannabinoid Receptor Agonist},
	journal = {Acs Chemical Biology},
	volume = {4},
	number = {2},
	year = {2009},
	note = {ISI Document Delivery No.: 410WNTimes Cited: 1Cited Reference Count: 19Pereira, Alban Pfeifer, Tom A. Grigliatti, Thomas A. Andersen, Raymond J.},
	month = {Feb},
	pages = {139-144},
	type = {Article},
	abstract = {A marine natural product extract library has been screened with a functional cell-based G-protein coupled receptor assay to find compounds capable of binding the human cannabinoid receptors CB1 and CB2. The methanol extract of the marine sponge Dasychalina fragilis collected in Papua New Guinea was active in the assay. Bioassay guided fractionation of the extract identified the phosphorylated sterol sulfate haplosamate A(1) as a cannabinoid receptor agonist. The high water solubility of haplosamate A(1) allowed exploration of its binding interactions with the human cannabinoid recepors in whole insect cells by means of saturation transfer double-difference NMR spectroscopy. This technique confirmed that haplosamate A(1) binds selectively to these receptors.},
	keywords = {DOCKING, ENDOCANNABINOID SYSTEM, inhibitors, INTEGRIN ALPHA(IIB)BETA(3), LIGAND-BINDING, PEPTIDE, PROTEIN, SPECTROSCOPY, STD-NMR},
	isbn = {1554-8929},
	url = {<Go to ISI>://000263609100008},
	author = {Pereira, A. and Pfeifer, T. A. and Grigliatti, T. A. and Andersen, R. J.}
}
@article {2456,
	title = {Nanomechanical Properties of Tenascin-X Revealed by Single-Molecule Force Spectroscopy},
	journal = {Journal of Molecular Biology},
	volume = {385},
	number = {4},
	year = {2009},
	note = {ISI Document Delivery No.: 403HJTimes Cited: 4Cited Reference Count: 35Jollymore, Ashlee Lethias, Claire Peng, Qing Cao, Yi Li, Hongbin},
	month = {Jan},
	pages = {1277-1286},
	type = {Article},
	abstract = {Tenascin-X is an extracellular matrix protein and binds a variety of molecules in extracellular matrix and on cell membrane. Tenascin-X plays important roles in regulating the structure and mechanical properties of connective tissues. Using single-molecule atomic force microscopy, we have investigated the mechanical properties of bovine tenascin-X in detail. Our results indicated that tenascin-X is an elastic protein and the fibronectin type III (FnIII) domains can unfold under a stretching force and refold to regain their mechanical stability upon the removal of the stretching force. All the 30 FnIII domains of tenascin-X show similar mechanical stability, mechanical unfolding kinetics, and contour length increment upon domain unfolding, despite their large sequence diversity. In contrast to the homogeneity in their mechanical unfolding behaviors, FnIII domains fold at different rates. Using the 10th FnIII domain of tenascin-X (TNXfn10) as a model system, we constructed a polyprotein chimera composed of alternating TNXfn10 and GB1 domains and used. atomic force microscopy to confirm that the mechanical properties of TNXfn10 are consistent with those of the FnIII domains of tenascin-X These results lay the foundation to further study the mechanical properties of individual FnIII domains and establish the relationship between point mutations and mechanical phenotypic effect on tenascin-X Moreover, our results provided the opportunity to compare the mechanical properties and design of different forms of tenascins. The comparison between tenascin-X and tenascin-C revealed interesting common as well as distinguishing features for mechanical unfolding and folding of tenascin-C and tenascin-X and will open up new avenues to investigate the mechanical. functions and architectural design of different forms of tenascins. (C) 2008 Elsevier Ltd. All rights reserved.},
	keywords = {AFM, BINDING, DEFICIENCY, DOMAINS, FAMILY, FnIII domains, IDENTIFICATION, III MODULES, MECHANICAL STABILITY, mechanical unfolding, microscopy, PROTEIN, single molecule force spectroscopy, tenascin},
	isbn = {0022-2836},
	url = {<Go to ISI>://000263073400022},
	author = {Jollymore, A. and Lethias, C. and Peng, Q. and Cao, Y. and Li, H. B.}
}
@article {2500,
	title = {Subdiffraction-Limit Two-Photon Fluorescence Microscopy for GFP-Tagged Cell Imaging},
	journal = {Biophysical Journal},
	volume = {97},
	number = {12},
	year = {2009},
	note = {ISI Document Delivery No.: 532QVTimes Cited: 1Cited Reference Count: 33Li, Qifeng Wu, Sherry S. H. Chou, Keng C.},
	month = {Dec},
	pages = {3224-3228},
	type = {Article},
	abstract = {We report applications of two-photon excitation fluorescence (2PEF) microscopy with subdiffraction-limit resolution for green-fluorescent-protein-tagged cell imaging. The microscope integrates 2PEF microscopy and stimulated emission depletion microscopy in one microscope that has the benefits of both techniques: intrinsic three-dimensional resolution, confined photobleaching, and subdiffraction-limit resolution. The subdiffraction-limit resolution was demonstrated by resolving green-fluorescent-protein-tagged caveolar vesicles located within a distance shorter than the diffraction limit of a regular 2PEF microscope, which is similar to 250 nm even with the best optics. The full width at half-maximum of the effective point-spread function for the 2PEF microscope was estimated to be similar to 54 nm.},
	keywords = {CAVEOLAE, NANOSCOPY, PROTEIN, RESOLUTION, STATES, STED MICROSCOPY, STIMULATED-EMISSION-DEPLETION},
	isbn = {0006-3495},
	url = {<Go to ISI>://000272765400020},
	author = {Li, Q. F. and Wu, S. S. H. and Chou, K. C.}
}
@article {2148,
	title = {{\textquoteright}Mechanical Engineering{\textquoteright} of Elastomeric Proteins: Toward Designing New Protein Building Blocks for Biomaterials},
	journal = {Advanced Functional Materials},
	volume = {18},
	number = {18},
	year = {2008},
	note = {ISI Document Delivery No.: 358QQTimes Cited: 6Cited Reference Count: 102Li, Hongbin},
	month = {Sep},
	pages = {2643-2657},
	type = {Review},
	abstract = {Elastomeric proteins are subject to stretching force under biological settings and play important roles in regulating the mechanical properties of a wide range of biological machinery. Elastomeric proteins also underlie the superb mechanical properties of many protein-based biomaterials. The developments of single molecule force spectroscopy have enabled the direct characterization of the mechanical properties of elastomeric proteins at the single molecule level and led to the new burgeoning field of research: single protein mechanics-and engineering. Combined, single molecule atomic force microscopy and protein engineering efforts are well under way to understand molecular determinants for the mechanical stability of elastomeric proteins and to develop methodologies to tune the mechanical properties of proteins in a rational and systematic fashion, which will lead to the {\textquoteright}mechanical engineering{\textquoteright} of elastomeric proteins. Here the current status of these experimental efforts is discussed and the successes and challenges in constructing novel proteins with tailored nanomechanical proteins are highlighted. The prospect of employing such engineered artificial elastomeric proteins as building blocks for the construction of biomaterials for applications ranging from material sciences to biomedical engineering is also discussed.},
	keywords = {ATOMIC-FORCE MICROSCOPY, BIOLOGICAL ROLES, DIHYDROFOLATE-REDUCTASE, EXTRACELLULAR-MATRIX PROTEIN, FLUORESCENT PROTEIN, IG DOMAIN, MOLECULAR-DYNAMICS SIMULATIONS, PROTEIN, SINGLE, TITIN IMMUNOGLOBULIN DOMAINS, UNFOLDING PATHWAYS},
	isbn = {1616-301X},
	url = {<Go to ISI>://000259933000001},
	author = {Li, H. B.}
}
@article {2034,
	title = {Single molecule force spectroscopy reveals engineered metal chelation is a general approach to enhance mechanical stability of proteins},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {105},
	number = {32},
	year = {2008},
	note = {ISI Document Delivery No.: 339EKTimes Cited: 16Cited Reference Count: 44Cao, Yi Yoo, Teri Li, Hongbin},
	month = {Aug},
	pages = {11152-11157},
	type = {Article},
	abstract = {Significant mechanical stability is an essential feature shared by many elastomeric proteins, which function as molecular springs in a wide variety of biological machinery and biomaterials of superb mechanical properties. Despite the progress in understanding molecular determinants of mechanical stability, it remains challenging to rationally enhance the mechanical stability of proteins. Using single molecule force spectroscopy and protein engineering techniques, we demonstrate that engineered bi-histidine metal chelation can enhance the mechanical stability of proteins significantly and reversibly. Based on simple thermodynamic cycle analysis, we engineered a bi-histidine metal chelation site into various locations of the small protein, GB1, to achieve preferential stabilization of the native state over the mechanical unfolding transition state of GB1 through the binding of metal ions. Our results demonstrate that the metal chelation can enhance the mechanical stability of GB1 by as much as 100 pN. Since bi-histidine metal chelation sites can be easily implemented, engineered metal chelation provides a general methodology to enhance the mechanical stability of a wide variety of proteins. This general approach in protein mechanics will enable the rational tuning of the mechanical stability of proteins. It will not only open new avenues toward engineering proteins of tailored nanomechanical properties, but also provide new approaches to systematically map the mechanical unfolding pathway of proteins.},
	keywords = {BINDING SITES, charge, DESIGN, DOMAINS, ELASTICITY, engineering, EXTRACELLULAR-MATRIX PROTEIN, mechanical unfolding, PROTEIN, protein mechanics, rational design, SIMULATIONS, STABILIZATION, STRENGTH, THERMOSTABILITY, TITIN},
	isbn = {0027-8424},
	url = {<Go to ISI>://000258560700024},
	author = {Cao, Y. and Yoo, T. and Li, H. B.}
}
@article {1612,
	title = {The structure of gelsolin bound to ATP},
	journal = {Journal of Molecular Biology},
	volume = {357},
	number = {3},
	year = {2006},
	note = {ISI Document Delivery No.: 030IYTimes Cited: 7Cited Reference Count: 28},
	month = {Mar},
	pages = {765-772},
	type = {Article},
	abstract = {Calcium activation of the actin-modifying properties of gelsolin is sensitive to ATP. Here, we show that soaking calcium-free gelsolin crystals in ATP-containing media results in ATP occupying a site that spans the two pseudosymmetrical halves of the protein. ATP binding involves numerous polar and hydrophobic contacts and is identical for the two copies of gelsolin related by non-crystallographic symmetry within the crystal. The gamma-phosphate of ATP participates in several charge-charge interactions consistent with the preference of gelsolin for ATP, as a binding partner, over ADP. In addition, disruption of the ATP-binding site through Ca2+ activation of gelsolin reveals why ATP binds more tightly to the inactive molecule, and suggests how the binding of ATP may modulate the sensitivity of gelsolin to calcium ions. Similarities between the ATP and PIP2 interactions with the C-terminal half of gelsolin are evident from their overlapping binding sites and in that both molecules bind more tightly in the absence of calcium ions. We propose a model for how PIP2 may bind to calcium-free gelsolin based on the ATP-binding site. (c) 2006 Elsevier Ltd. All rights reserved.},
	keywords = {5-BISPHOSPHATE, actin, ATP, BINDING-SITE, calcium, CRYSTAL-STRUCTURE, DOMAIN, gelsolin, HUMAN-PLASMA GELSOLIN, IDENTIFICATION, PHOSPHATIDYLINOSITOL 4, PIP2, PROTEIN, TERMINAL HALF},
	isbn = {0022-2836},
	url = {<Go to ISI>://000236629300007},
	author = {Urosev, D. and Ma, Q. and Tan, A. L. C. and Robinson, R. C. and Burtnick, L. D.}
}
@article {1618,
	title = {Sub-angstrom conformational changes of a single molecule captured by AFM variance analysis},
	journal = {Biophysical Journal},
	volume = {90},
	number = {10},
	year = {2006},
	note = {ISI Document Delivery No.: 034CETimes Cited: 20Cited Reference Count: 34},
	month = {May},
	pages = {3806-3812},
	type = {Article},
	abstract = {A system{\textquoteright}s equilibrium variance can be analyzed to probe its underlying dynamics at higher resolution. Here, using single-molecule atomic-force microscope techniques, we show how the variance in the length of a single dextran molecule can be used to establish thermodynamic equilibrium and to detect conformational changes not directly observable with other methods. Dextran is comprised of a chain of pyranose rings that each undergoes an Angstrom-scale transition from a chair to boat conformation under a stretching force. Our analysis of the variance of the molecule{\textquoteright}s fluctuations verifies equilibrium throughout the force-extension curve, consistent with the expected thermodynamic ensemble. This validates further analysis of the variance in the transition region, which reveals an intermediate conformation between the chair and the boat on the sub-Angstrom scale. Our test of thermal equilibrium as well as our variance analysis can be readily extended to a wide variety of molecules, including proteins.},
	keywords = {ATOMIC-FORCE MICROSCOPE, CHAIR-BOAT TRANSITIONS, HIGH-RESOLUTION, LIQUIDS, MECHANICAL FORCE, POLYSACCHARIDES, PROTEIN, RNA MOLECULES, SPECTROSCOPY, UBIQUITIN},
	isbn = {0006-3495},
	url = {<Go to ISI>://000236901400043},
	author = {Walther, K. A. and Brujic, J. and Li, H. B. and Fernandez, J. M.}
}
@article {1289,
	title = {Arylfluoroborates and alkylfluorosilicates as potential PET imaging agents: High-yielding aqueous biomolecular F-18-labeling},
	journal = {Journal of the American Chemical Society},
	volume = {127},
	number = {38},
	year = {2005},
	note = {ISI Document Delivery No.: 968OCTimes Cited: 29Cited Reference Count: 32},
	month = {Sep},
	pages = {13094-13095},
	type = {Article},
	keywords = {AVIDIN, biotin, BORONIC ACIDS, CROSS-COUPLING REACTIONS, F-18, FRAGMENT, MICROPET, MONOCLONAL-ANTIBODY, PROTEIN, STATE},
	isbn = {0002-7863},
	url = {<Go to ISI>://000232170800007},
	author = {Ting, R. and Adam,Michael J. and Ruth, T. J. and Perrin,David M.}
}
@article {1289,
	title = {Arylfluoroborates and alkylfluorosilicates as potential PET imaging agents: High-yielding aqueous biomolecular F-18-labeling},
	journal = {Journal of the American Chemical Society},
	volume = {127},
	number = {38},
	year = {2005},
	note = {ISI Document Delivery No.: 968OCTimes Cited: 29Cited Reference Count: 32},
	month = {Sep},
	pages = {13094-13095},
	type = {Article},
	keywords = {AVIDIN, biotin, BORONIC ACIDS, CROSS-COUPLING REACTIONS, F-18, FRAGMENT, MICROPET, MONOCLONAL-ANTIBODY, PROTEIN, STATE},
	isbn = {0002-7863},
	url = {<Go to ISI>://000232170800007},
	author = {Ting, R. and Adam,Michael J. and Ruth, T. J. and Perrin,David M.}
}
@article {1223,
	title = {Letter to the editor: Backbone chemical shift assignments of the LexA catalytic domain in its active conformation},
	journal = {Journal of Biomolecular Nmr},
	volume = {31},
	number = {4},
	year = {2005},
	note = {ISI Document Delivery No.: 931SKTimes Cited: 1Cited Reference Count: 7},
	month = {Apr},
	pages = {371-372},
	type = {Article},
	keywords = {auto-proteolysis, DYNAMICS, LexA, N-15 NMR RELAXATION, NMR ASSIGNMENTS, PROTEIN, SOS response},
	isbn = {0925-2738},
	url = {<Go to ISI>://000229505400016},
	author = {Okon, M. and Pfuetzner, R. and Vuckovic, M. and Little, J. W. and Strynadka, N. C. J. and McIntosh, L. P.}
}
@article {1271,
	title = {Modulation of the G(2) cell cycle checkpoint by sesquiterpene lactones psilostachyins A and C isolated from the common ragweed Ambrosia artemisiifolia},
	journal = {Planta Medica},
	volume = {71},
	number = {10},
	year = {2005},
	note = {ISI Document Delivery No.: 985TLTimes Cited: 8Cited Reference Count: 30},
	month = {Oct},
	pages = {938-943},
	type = {Article},
	abstract = {A phenotypic cell-based assay for inhibitors of the G(2) DNA damage checkpoint was used to screen plant extracts from the US National Cancer Institute Natural Products Repository. It revealed activity in a methanol extract from the common ragweed Ambrosia artemisiifolia. Assay-guided fractionation led to the identification of the sesquiterpene lactones psilostachyins A and C as novel checkpoint inhibitors. Elimination of their alpha,beta-unsaturated carbonyl group caused a loss of activity, suggesting that the compounds can bind covalently to target proteins through Michael addition. Psilostachyins A and C also blocked cells in mitosis and caused the formation of aberrant microtubule spindles. However, the compounds did not interfere with microtubule polymerization in vitro. The related sesquiterpene lactones psilostachyin 13, paulitin and isopaulitin were also isolated from the same extract but showed no checkpoint inhibition. The identification of the target(s) of psilostachyins A and C may provide further insight into the signalling pathways involved in cell cycle arrest and mitotic progression.},
	keywords = {Ambrosia artemisiffolia, CAFFEINE, CANCER, cell cycle, checkpoint, CHK1, DILACTONE, DNA-DAMAGE CHECKPOINT, G(2) phase, INHIBITION, KINASE, MCF-7 CELLS, mitosis, P53, PROTEIN, UCN-01},
	isbn = {0032-0943},
	url = {<Go to ISI>://000233401400009},
	author = {Sturgeon, C. M. and Craig, K. and Brown, C. and Rundle, N. T. and Andersen, R. J. and Roberge, M.}
}
@article {1198,
	title = {Strongylophorine-26, a Rho-dependent inhibitor of tumor cell invasion that reduces actin stress fibers and induces nonpolarized lamellipodial extensions},
	journal = {Molecular Cancer Therapeutics},
	volume = {4},
	number = {5},
	year = {2005},
	note = {ISI Document Delivery No.: 926DETimes Cited: 6Cited Reference Count: 37},
	month = {May},
	pages = {772-778},
	type = {Article},
	abstract = {Strongylophorine-26, a new meroditerpenoid, was recently identified as an inhibitor of cancer cell invasion. This study was undertaken to characterize its mechanism of action. We find that strongylophorine-26 inhibits the motility of MDA-MB-231 breast carcinoma cells on a plastic surface. Upon addition of strongylophorine-26, rapid cell contraction and depolarization occurred, followed by spreading and flattening of the entire cell. Treated cells exhibited increased membrane ruffling throughout and extended lamellipodia in all directions. Strongylophorine-26 induced a decrease in actin stress fibers, a dramatic increase in the size and number of focal adhesions, and the appearance of a dense meshwork of actin filaments around the cell periphery. Strongylophorine-26 caused a transient activation of the small GTPase Rho and treatment with the Rho inhibitor C3 exoenzyme abrogated the anti-invasive activity of strongylophorine-26. These effects are distinct from those of many motility and angiogenesis inhibitors that seem to act by a common mechanism involving the induction of actin stress fibers. This difference in mechanism of action sets strongylophorine-26 apart as an experimental anticancer agent and indicates that pharmacologic inhibition of cell migration may be achieved by mechanisms not involving the stabilization of actin stress fibers.},
	keywords = {ACTIVATION, ANGIOGENESIS, CYTOSKELETON, FAMILY, FOCAL ADHESIONS, KINASE, MIGRATION, MOTILITY, PROTEIN, SMALL GTPASE},
	isbn = {1535-7163},
	url = {<Go to ISI>://000229102300009},
	author = {McHardy, L. M. and Warabi, K. and Andersen, R. J. and Roskelley, C. D. and Roberge, M.}
}
@article {1233,
	title = {Variable control of Ets-1 DNA binding by multiple phosphates in an unstructured region},
	journal = {Science},
	volume = {309},
	number = {5731},
	year = {2005},
	note = {ISI Document Delivery No.: 941KDTimes Cited: 66Cited Reference Count: 30},
	month = {Jul},
	pages = {142-145},
	type = {Article},
	abstract = {Cell signaling that culminates in posttranslational modifications directs protein activity. Here we report how multiple Ca2+-dependent phosphorylation sites within the transcription activator Ets-1 act additively to produce graded DNA binding affinity. Nuclear magnetic resonance spectroscopic analyses show that phosphorylation shifts Ets-1 from a dynamic conformation poised to bind DNA to a well-folded inhibited state. These phosphates lie in an unstructured flexible region that functions as the allosteric effector of autoinhibition. Variable phosphorylation thus serves as a "rheostat" for cell signaling to fine-tune transcription at the level of DNA binding.},
	keywords = {allosteric regulation, AUTOINHIBITION, DOMAIN, DYNAMICS, NMR-SPECTROSCOPY, PHOSPHORYLATION, PROTEIN, SITES, TRANSACTIVATION, TRANSCRIPTION FACTOR NFAT1},
	isbn = {0036-8075},
	url = {<Go to ISI>://000230212800079},
	author = {Pufall, M. A. and Lee, G. M. and Nelson, M. L. and Kang, H. S. and Velyvis, A. and Kay, L. E. and McIntosh, L. P. and Graves, B. J.}
}
@article {910,
	title = {Synthesis of well-defined environmentally responsive polymer brushes by aqueous ATRP},
	journal = {Macromolecules},
	volume = {37},
	number = {3},
	year = {2004},
	note = {ISI Document Delivery No.: 771TWTimes Cited: 102Cited Reference Count: 56},
	month = {Feb},
	pages = {734-743},
	type = {Article},
	abstract = {Functionalized anionic polystyrene latex particles with ATRP initiators were synthesized by surfactant-free shell-growth emulsion polymerization of styrene and 2-(2{\textquoteright}-chloropropionato)ethyl acrylate (HEA-Cl). N-Isopropylacrylamide (NIPAM) was polymerized from these particles by surface-initiated aqueous ATRP using PMDETA/CuCl and HMTETA/CuCl catalysts to synthesize poly(N-isopropylacrylamide) (PNIPAM) brushes. The grafted latexes were characterized for molecular weight of the PNIPAM chains, grafting density, and hydrodynamic thickness of the grafted polymer layer. Molecular weights of the grafted PNIPAM chains depended on the monomer concentration, concentration of copper(II) complex, and the presence of external initiator in the reaction medium. M-n of the grafted chains increases with increase in the monomer concentration and decreases with addition of copper(II) complex and external initiator. The HMTETA/CuCl catalyst produces higher molecular weight chains than PMDETA/CuCl. Molecular weights from similar to50 000 to 800 000 with low polydispersities, between 1.25 and 1.4, were achieved. The grafting density of PNIPAM on the surface increases with increasing monomer concentration and decreases with addition of copper(II) catalyst and external initiator. Block copolymerization of N,N-dimethylacrylamide from PNIPAM-grafted latex demonstrated that the chains are terminated with a chlorine atom, and the grafting reactions are taking place by the ATRP mechanism. The hydrodynamic thickness (HT) of the grafted PNIPAM layer scales as DP0.66 (where DP = degree of polymerization) at constant grafting density (chains/nm(2)). The HT values for PNIPAM brushes are sensitive to temperature and salt concentration. Since the transition from extended coil to collapsed structure occurs over a range of temperature and salt concentration, it follows a second-order transition, as predicted by theory. The thickness of the collapsed brush is sensitive to the type of stimulus used to induce the phase transition.},
	keywords = {GLOBULE TYPE TRANSITIONS, INTERFACES, N-DIMETHYLACRYLAMIDE) BRUSHES, PARTICLES, POLY(N, POLY(N-ISOPROPYLACRYLAMIDE), PROTEIN, SILICA, SURFACE-INITIATED POLYMERIZATIONS, TEMPERATURE, TRANSFER RADICAL POLYMERIZATION},
	isbn = {0024-9297},
	url = {<Go to ISI>://000188803000010},
	author = {Kizhakkedathu, J. N. and Norris-Jones, R. and Brooks, D. E.}
}
@article {713,
	title = {Characterizing the pH-dependent stability and catalytic mechanism of the family 11 xylanase from the alkalophilic Bacillus agaradhaerens},
	journal = {Carbohydrate Research},
	volume = {338},
	number = {5},
	year = {2003},
	note = {ISI Document Delivery No.: 645XBTimes Cited: 6Cited Reference Count: 38},
	month = {Feb},
	pages = {415-421},
	type = {Article},
	abstract = {The xylanase, BadX, from the alkalophilic Bacillus agaradhaerens was cloned, expressed and studied in comparison to a related family 11 xylanase, BcX, from B. circulans. Despite the alkaline versus neutral conditions under which these bacteria grow, BadX and BcX both exhibit optimal activity near pH 5.6 using the substrate omicron-nitrophenyl beta-xylobioside. Analysis of the bell-shaped activity profile of BadX yielded apparent pK(a) values of 4.2 and 7.1, assignable to its nucleophile Glu94 and general acid Glu184, respectively. In addition to having an similar to 10-fold higher k(cat)/K-m value with this substrate at pH 6 and 40 degreesC, BadX has significantly higher thermal stability than BcX under neutral and alkaline conditions. This enhanced stability, rather than a shift in its pH-optimum, may allow BadX to hydrolyze xylan under conditions of elevated temperature and pH. (C) 2003 Elsevier Science Ltd. All rights reserved.},
	keywords = {bacillus xylanase, CIRCULANS XYLANASE, CLASSIFICATION, electrostatic, extremophile, glycosidase, GLYCOSYL-ENZYME INTERMEDIATE, HYDROLASES, interactions, NMR ASSIGNMENTS, pH-dependent mechanism, PK(A), PROTEIN, STABILITY, THERMOSTABILITY},
	isbn = {0008-6215},
	url = {<Go to ISI>://000181004800004},
	author = {Poon, D. K. Y. and Webster, P. and Withers, S. G. and McIntosh, L. P.}
}
@article {681,
	title = {Conformations of gas-phase lysozyme ions produced from two different solution conformations},
	journal = {Analytical Chemistry},
	volume = {75},
	number = {6},
	year = {2003},
	note = {ISI Document Delivery No.: 657PQTimes Cited: 15Cited Reference Count: 41},
	month = {Mar},
	pages = {1325-1330},
	type = {Article},
	abstract = {Near pH 2.0, lysozyme in water is in its native conformation, and in water/methanol (2/8) it adopts a helical denatured conformation (Kamatari et al. Protein Sci. 1998, 7, 681-688). Hydrogen/deuterium (H/D) exchange of lysozyme in solution confirms that it is partially unfolded at pH 2.0 in water/methanol (v/v = 2/8). With electrospray ionization (ESI) mass spectrometry (MS), lysozyme in water produces ions with charges +7 to +12, with the greatest intensity at +10, whereas lysozyme in water/methanol (2/8) produces ions with charges +6 to +12 with the greatest intensity at +7. Thus, lysozyme is an exception to the rule that a protein denatured in solution forms higher charge states than the same protein in its folded native conformations in solution. Because the same charge states are produced from these two solution conformations, a direct comparison of the properties of the gas-phase ions produced from two very different solution conformations is possible. The conformations of lysozyme ions in the gas phase were studied using cross section measurements and gas-phase H/D exchange. Similar cross sections and H/D exchange levels were observed for same-charge states of lysozyme ions formed from the native and helical denatured conformations in solution. Cross sections show that the ions have compact structures. Thus, disulfide-intact gaseous lysozyme ions generated from the denatured state in water/methanol (2/8) refold into compact structures in the gas phase on a time scale of milliseconds or less.},
	keywords = {COLLISION, CROSS-SECTIONS, CYTOCHROME-C, EGG-WHITE LYSOZYME, H/D EXCHANGE, HYDROGEN-DEUTERIUM EXCHANGE, HYDROGEN/DEUTERIUM EXCHANGE, IONIZATION MASS-SPECTROMETRY, IONS, OF-FLIGHT SYSTEM, PROTEIN, UNFOLDING DYNAMICS},
	isbn = {0003-2700},
	url = {<Go to ISI>://000181675900014},
	author = {Mao, D. M. and Babu, K. R. and Chen, Y. L. and Douglas, D. J.}
}
@article {597,
	title = {Drug release characteristics of lipid based benzoporphyrin derivative},
	journal = {Journal of Pharmacy and Pharmaceutical Sciences},
	volume = {6},
	number = {1},
	year = {2003},
	note = {ISI Document Delivery No.: 679QJTimes Cited: 21Cited Reference Count: 17},
	month = {Jan-Apr},
	pages = {13-19},
	type = {Article},
	abstract = {PURPOSE. The purpose of this study was to examine the transfer of verteporfin (BPDMA) from its lipid based formulation to serum proteins. METHODS. As a result of BPDMA being confined to the lipid phase, it was found that fluorescence from the photosensitizer was highly concentration quenched. This phenomenon was used to demonstrate rapid transfer of lipid-based drug to various plasma components such as albumin and lipoproteins. Gel electrophoresis was used to show transfer of drug to lipoproteins. RESULTS. Loss of fluorescence quenching showed rapid transfer of the drug from its lipid based formulation to serum proteins. Gel electrophoresis showed that both the drug and phospholipid components were transferred to the lipoprotein fraction concurrently. The electrophoretic mobility of plasma lipoproteins was increased as a result of their interaction with lipid-based BPDMA. It was also shown that the lipid-based structures were readily destabilized in the presence of relatively low concentrations of plasma, and that liposomes of this lipid composition were highly unlikely to be found intact in the circulation following intravenous injection. CONCLUSIONS. Verteporfin is rapidly transferred from its lipid based formulation to serum proteins. This rapid transfer, particularly to lipoproteins, provides a mechanism for its rapid delivery to cells.},
	keywords = {DENSITY LIPOPROTEINS, DESTABILIZATION, LIPOSOMES, PHOTODYNAMIC THERAPY, PLASMA-LIPOPROTEINS, PROTEIN, TUMORS},
	isbn = {1482-1826},
	url = {<Go to ISI>://000182933200002},
	author = {Chowdhary, R. K. and Shariff, I. and Dolphin, D.}
}
@article {433,
	title = {Caminoside A, an antimicrobial glycolipid isolated from the marine sponge Caminus sphaeroconia},
	journal = {Organic Letters},
	volume = {4},
	number = {23},
	year = {2002},
	note = {ISI Document Delivery No.: 614DUTimes Cited: 21Cited Reference Count: 13},
	month = {Nov},
	pages = {4089-4092},
	type = {Article},
	abstract = {[GRAPHICS] Extracts of the marine sponge Caminus sphaeroconia showed potent activity in a screen for bacterial type III secretion inhibitors. Bioassay guided fractionation of the extract led to the isolation of the novel antimicrobial glycollpid caminoside A (1). The structure of caminoside A was elucidated by analysis of spectroscopic data and chemical degradation.},
	keywords = {ENTEROPATHOGENIC ESCHERICHIA-COLI, HOST-CELLS, PROTEIN, RECEPTOR, SECRETION, SYSTEMS},
	isbn = {1523-7060},
	url = {<Go to ISI>://000179173700026},
	author = {Linington, R. G. and Robertson, M. and Gauthier, A. and Finlay, B. B. and van Soes, R. and Andersen, R. J.}
}
@article {342,
	title = {A comparison of three- and four-helix bundle TASP molecules},
	journal = {Journal of Peptide Science},
	volume = {8},
	number = {6},
	year = {2002},
	note = {ISI Document Delivery No.: 563ZTTimes Cited: 14Cited Reference Count: 19},
	month = {Jun},
	pages = {275-282},
	type = {Article},
	abstract = {We have designed, synthesized and characterized three- and four-helix bundle template-assembled synthetic proteins (TASPs). The TASPs were synthesized using disulphide bonds between the peptides and either the cyclotribenzylene (CTB) template, or the cavitand (BOWL) template, to form the three- and four helix bundles, respectively. The TASPs were constructed using peptides that were linked via their N-termini (peptide CGGGEELLKKXEELLKKG, where X = L, I, Nle or V), or via their C-termini (peptide GEELLKKLEELLKKGGGC). Each TASP was assayed for its structure, stability, {\textquoteright}native-like{\textquoteright} characteristics and whether it was a monomer in solution. All TASPs were found to be highly helical, and highly resistant to chemical denaturation using guanidine hydrochloride (GnHCl). Analysis of the GnHCl-induced unfolding curves of the different TASPs demonstrated stability differences based on the number of helices in the bundle, the end of the helix that was attached to the template, and the identity of the core amino acid. The TASPs all had molten-globule structure, which is (generally) consistent with a degenerate sequence in the core. The four-helix bundle TASPs appeared to be monomers in solution, whereas there is some evidence that the three-helix bundle TASPs are weakly self associating. Copyright. (C) 2002 European Peptide Society and John Wiley Sons, Ltd.},
	keywords = {4-HELIX BUNDLES, DESIGN, four-helix bundle, PROTEIN, STABILITY, TASP, template assembled synthetic protein, three-helix bundle},
	isbn = {1075-2617},
	url = {<Go to ISI>://000176289000005},
	author = {Causton, A. S. and Sherman, J. C.}
}
@article {5031,
	title = {Artificial nucleases},
	journal = {Chembiochem},
	volume = {2},
	number = {10},
	year = {2001},
	note = {ISI Document Delivery No.: 479NGTimes Cited: 54Cited Reference Count: 25},
	month = {Oct},
	pages = {735-740},
	type = {Article},
	abstract = {The oxidation of DNA and RNA provides a facile approach for investigating the interaction of nucleic acids wit proteins and oligonucleotides In this article, we have outlined our understanding of the mechanism of DNA scission by 1,10-phenanthroline-copper(I) in the presence of hydrogen peroxide. We also discuss results obtained by using 1,10-phenanthroline - oligonucleotide conjugates in probing the size of the transcriptionally active open complex. Finally, we outline an effective method for converting DNA-binding proteins into site-specific modification agents by using 1,10-phenanthroline-copper(I).},
	keywords = {1, 10-PHENANTHROLINE-COPPER ION, chemical, COLI RNA-POLYMERASE, COMPLEX, copper, DNA, DNA cleavage, DNA recognition, ESCHERICHIA-COLI, NUCLEASE, nucleic acids, OLIGONUCLEOTIDES, PROTEIN, SITE-SPECIFIC NUCLEASE, TRANSCRIPTION INITIATION},
	isbn = {1439-4227},
	url = {<Go to ISI>://000171410000003},
	author = {Chen, C. H. B. and Milne, L. and Landgraf, R. and Perrin,David M. and Sigman, D. S.}
}
@article {5175,
	title = {The disintegration of a molecule: The role of gelsolin in FAF, familial amyloidosis (Finnish type)},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {98},
	number = {5},
	year = {2001},
	note = {ISI Document Delivery No.: 407EHTimes Cited: 8Cited Reference Count: 13},
	month = {Feb},
	pages = {2117-2118},
	type = {Editorial Material},
	keywords = {actin filament, MECHANISM, MODEL, PROTEIN},
	isbn = {0027-8424},
	url = {<Go to ISI>://000167258900003},
	author = {Robinson, R. C. and Choe, S. Y. and Burtnick, L. D.}
}
@article {5098,
	title = {Dissecting the electrostatic interactions and pH-dependent activity of a family 11 glycosidase},
	journal = {Biochemistry},
	volume = {40},
	number = {34},
	year = {2001},
	note = {ISI Document Delivery No.: 466CYTimes Cited: 56Cited Reference Count: 50},
	month = {Aug},
	pages = {10115-10139},
	type = {Article},
	abstract = {Previous studies of the low molecular mass family 11 xylanase from Bacillus circulans show that the ionization state of the nucleophile (GIu78, pK(a) 4.6) and the acid/base catalyst (Glu 172, pK(a) 6.7) gives rise to its pH-dependent activity profile. Inspection of the crystal structure of BCX reveals that Glu78 and Glu172 are in very similar environments and are surrounded by several chemically equivalent and highly conserved active site residues. Hence, there are no obvious reasons why their apparent pKa values are different. To address this question, a mutagenic approach was implemented to determine what features establish the pKa values (measured directly by C-13 NMR and indirectly by pH-dependent activity profiles) of these two catalytic carboxylic acids. Analysis of several BCX variants indicates that the ionized form of Glu78 is preferentially stabilized over that of Glu 172 in part by stronger hydrogen bonds contributed by two well-ordered residues, namely, Tyr69 and Gln127. In addition, theoretical pKa calculations show that Glu78 has a lower pKa value than Glu 172 due to a smaller desolvation energy and more favorable background interactions with permanent partial charges and ionizable groups within the protein. The pKa value of Glu172 is in turn elevated due to electrostatic repulsion from the negatively charged glutamate at position 78. The results also indicate that all of the conserved active site residues act concertedly in establishing the pKa values of Glu78 and Glu 172, with no particular residue being singly more important than any of the others. In general, residues that contribute positive charges and hydrogen bonds serve to lower the pKa values of Glu78 and Glu172. The degree to which a hydrogen bond lowers a pKa value is largely dependent on the length of the hydrogen bond (shorter bonds lower pKa values more) and the chemical nature of the donor (COOH > OH > CONH2). In contrast, neighboring carboxyl groups can either lower or raise the pKa values of the catalytic glutamic acids depending upon the electrostatic linkage of the ionization constants of the residues involved in the interaction. While the pH optimum of BCX can be shifted from -1.1 to +0.6 pH units by mutating neighboring residues within the active site, activity is usually compromised due to the loss of important ground and/or transition state interactions. These results suggest that the pH optima of an enzyme might be best engineered by making strategic amino acid substitutions, at positions outside of the "core" active site, that electrostatically influence catalytic residues without perturbing their immediate structural environment.},
	keywords = {ASSIGNMENTS, BACILLUS-CIRCULANS XYLANASE, CATALYSIS, GLYCOSYL-ENZYME INTERMEDIATE, KINETIC-ANALYSIS, MASS-SPECTROMETRY, MECHANISMS, NMR, PK(A), PROTEIN, SITE NUCLEOPHILE, structures},
	isbn = {0006-2960},
	url = {<Go to ISI>://000170627800014},
	author = {Joshi, M. D. and Sidhu, G. and Nielsen, J. E. and Brayer, G. D. and Withers, S. G. and McIntosh, L. P.}
}
@article {5004,
	title = {The methanol-induced conformational transitions of beta-lactoglobulin, cytochrome c, and ubiquitin at low pH: A study by electrospray ionization mass spectrometry},
	journal = {Journal of the American Society for Mass Spectrometry},
	volume = {12},
	number = {3},
	year = {2001},
	note = {ISI Document Delivery No.: 408WBTimes Cited: 45Cited Reference Count: 51},
	month = {Mar},
	pages = {317-328},
	type = {Article},
	abstract = {The methanol-induced conformational transitions under acidic conditions for beta -lactoglobulin, cytochrome c, and ubiquitin, representing three different classes of proteins with beta -sheets, alpha -helices, and both alpha -helices and beta -sheets, respectively, are studied under equilibrium conditions by electrospray ionization mass spectrometry (ESI-MS). The folding states of proteins in solution are monitored by the charge state distributions that they produce during ESI and by hydrogen/deuterium (H/D) exchange followed by ESI-MS. The changes in charge state distributions are correlated with earlier studies by optical and other methods which have shown that, in methanol, these proteins form partially unfolded intermediates with induced ct-helix structure. Intermediate states formed at about 35\% methanol concentration are found to give bimodal charge state distributions. The same rate of H/D exchange is shown by the two contributions to the bimodal distributions. This suggests the intermediates are highly flexible and may consist of a mixture of two or more rapidly interconverting conformers. H/D exchange of proteins followed by ESI-MS shows that helical denatured states, populated at around 50\% methanol concentration, transform into more protected structures with further increases in methanol concentration, consistent with previous circular dicroism studies. These more protected structures still produce high charge states in ESI, similar to those of the fully denatured proteins. (C) 2001 American Society for Mass Spectrometry.},
	keywords = {2-DIMENSIONAL NMR, ALPHA-HELIX, AMIDE HYDROGEN-EXCHANGE, COMPLETE SEQUENCE, DENATURED STATES, DEUTERIUM-EXCHANGE, INTERMEDIATE, MYOGLOBIN, PROTEIN, SOLVENT},
	isbn = {1044-0305},
	url = {<Go to ISI>://000167349200010},
	author = {Babu, K. R. and Moradian, A. and Douglas, D. J.}
}
@article {4780,
	title = {Analysis of the dynamic properties of Bacillus circulans xylanase upon formation of a covalent glycosyl-enzyme intermediate},
	journal = {Protein Science},
	volume = {9},
	number = {3},
	year = {2000},
	note = {ISI Document Delivery No.: 295XWTimes Cited: 16Cited Reference Count: 56},
	month = {Mar},
	pages = {512-524},
	type = {Article},
	abstract = {NMR spectroscopy was used to search for mechanistically significant differences in the local mobility of the main-chain amides of Bacillus circulans xylanase (BCX) in its native and catalytically competent covalent glycosyl-enzyme intermediate states. N-15 T-1, T-2, and N-15{H-1} NOE values were measured for similar to 120 out of 178 peptide groups in both the apo form of the protein and in BCX covalently modified at position Glu78 with a mechanism-based 2-deoxy-2-fluoro-beta-xylobioside inactivator. Employing the model-free formalism of Lipari and Szabo, the measured relaxation parameters were used to calculate a global correlation time ( tau(m)) for the protein in each form (9.2 +/- 0.2 ns for apo-BCX; 9.8 +/- 0.3 ns for the modified protein), as well as individual order parameters for the main-chain NH bond vectors. Average values of the order parameters for the protein in the apo and complexed forms were S-2 = 0.86 +/- 0.04 and S-2 = 0.91 +/- 0.04, respectively. No correlation is observed between these order parameters and the secondary structure, solvent accessibility, or hydrogen bonding patterns of amides in either form of the protein. These results demonstrate that the backbone of BCX is well ordered in both states and that formation of the,glycosyl-enzyme intermediate leads to little change, in any, in the dynamic properties of BCX on the time scales sampled by N-15-NMR relaxation measurements.},
	keywords = {ACTIVE-SITE NUCLEOPHILE, ANISOTROPIC ROTATIONAL, BACKBONE DYNAMICS, BINDING, BURIED NEUTRAL HISTIDINE, DIFFUSION, glucanase, GLYCOSYL-ENZYME INTERMEDIATE, MAGNETIC-RESONANCE RELAXATION, MODEL-FREE APPROACH, N-15 NMR RELAXATION, NMR, order parameter, PROTEIN, PROTEINS, relaxation dynamics, SIDE-CHAIN RESONANCES, STRUCTURE},
	isbn = {0961-8368},
	url = {<Go to ISI>://000085994800009},
	author = {Connelly, G. P. and Withers, S. G. and McIntosh, L. P.}
}
@article {4305,
	title = {Optimization and immunological characterization of a photochemically coupled lysergic acid diethylamide (LSD) immunogen},
	journal = {Bioconjugate Chemistry},
	volume = {9},
	number = {5},
	year = {1998},
	note = {ISI Document Delivery No.: 125MYTimes Cited: 2Cited Reference Count: 41},
	month = {Sep-Oct},
	pages = {596-603},
	type = {Article},
	abstract = {A photoreactive heterobifunctional linker was used to prepare an immunogen in which lysergic acid diethylamide was indirectly coupled to keyhole limpet hemocyanin at multiple sites on the drug. It was possible to attach approximately 35 drug molecules to each protein using approximately equal amounts of both species during the reaction. The presence of buffer components or water severely compromised reaction efficiency, as estimated from the molar substitution ratio. Factors such as excess linker, pH, irradiation of dry matrix in the absence of buffer, and the drug/protein ratio used during photolysis were shown to have pronounced effects on reaction efficiency. Structural insights regarding immunogen coupling were obtained by determining the specificities of antibodies which were raised against the immunogen. Cross-reactivity data indicated that haptenation of protein likely occurred at positions N1 and N6 of lysergic acid diethylamide, which is plausible given the electrophilicity of the photogenerated aryl nitrene.},
	keywords = {BINDING, CROSS-LINKING REAGENTS, EPITOPE, FUNCTIONALIZED PERFLUOROPHENYL AZIDES, IMMUNOASSAY, IONIZATION MASS-SPECTROMETRY, photolysis, PROTEIN, RADIOIMMUNOASSAY, SERUM-ALBUMIN},
	isbn = {1043-1802},
	url = {<Go to ISI>://000076242400008},
	author = {Kerrigan, S. and Brooks, D. E.}
}
@article {4029,
	title = {Acid-induced unfolding of cytochrome c at different methanol concentrations: Electrospray ionization mass spectrometry specifically monitors changes in the tertiary structure},
	journal = {Biochemistry},
	volume = {36},
	number = {40},
	year = {1997},
	note = {ISI Document Delivery No.: YA264Times Cited: 132Cited Reference Count: 51},
	month = {Oct},
	pages = {12296-12302},
	type = {Article},
	abstract = {The acid-induced denaturation of ferricytochrome c (cyt c) was examined in aqueous solutions containing different concentrations of methanol by electrospray ionization mass spectrometry (ESI MS) and optical spectroscopy. Circular dichroism, fluorescence, and absorption spectroscopy show that at a low concentration of methanol (3\%) a decrease in pH induces a cooperative unfolding transition at around pH 2.6 that is accompanied by a breakdown of the native secondary and tertiary structure of the protein. In 50\% methanol the breakdown of the tertiary structure occurs at around pH 4.0, whereas the alpha-helical content remains largely intact over the whole pH range studied. In ESI MS different protein conformations in solution are monitored by the different charge state distributions they generate during ESI. The ESI mass spectra recorded at near-neutral pH for both methanol concentrations are very similar and show a maximum at (cyt c + 8H(+))8(+). Despite the different conformations of the protein in solution, the acid-denatured states for the two methanol concentrations also show very similar mass spectra with a maximum at (cyt c + 17H(+))17(+). This indicates that the charge state distribution generated during EST is not sensitive to the differences in the secondary structure of the denatured protein. The observed transition from low to high charge states is due to the breakdown of the tertiary structure in both cases. These findings suggest that ESI MS might be a general method to selectively monitor changes in the tertiary structure of proteins.},
	keywords = {ALPHA-HELIX, BETA-LACTOGLOBULIN, CIRCULAR-DICHROISM, DENATURED, FERRICYTOCHROME-C, HEME, PARTIALLY FOLDED STATE, PROBING CONFORMATIONAL-CHANGES, PROTEIN, STATE, TRIFLUOROETHANOL},
	isbn = {0006-2960},
	url = {<Go to ISI>://A1997YA26400034},
	author = {Konermann, L. and Douglas, D. J.}
}
@article {3920,
	title = {The crystal structure of plasma gelsolin: Implications for actin severing, capping, and nucleation},
	journal = {Cell},
	volume = {90},
	number = {4},
	year = {1997},
	note = {ISI Document Delivery No.: XT066Times Cited: 164Cited Reference Count: 50},
	month = {Aug},
	pages = {661-670},
	type = {Article},
	abstract = {The structure of gelsolin has been determined by crystallography and comprises six structurally related domains that, in a Ca2+-free environment, pack together to form a compact globular structure in which the putative actin-binding sequences are not sufficiently exposed to enable binding to occur. We propose that binding Ca2+ can release the connections that join the N- and C-terminal halves of gelsolin, enabling each half to bind actin relatively independently. Domain shifts are proposed in response to Ca2+ as bases for models of how gelsolin acts to sever, cap, or nucleate F-actin filaments. The structure also invites discussion of polyphosphoinositide binding to segment 2 and suggests how mutation at Asp-187 could initiate a series of events that lead to deposition of amyloid plaques, as observed in victims of familial amyloidosis (Finnish type).},
	keywords = {AMYLOIDOSIS, BINDING DOMAIN, calcium, DEFINITION, F-ACTIN, FILAMENT, IDENTIFICATION, PROTEIN, SEQUENCE, VILLIN},
	isbn = {0092-8674},
	url = {<Go to ISI>://A1997XT06600010},
	author = {Burtnick, L. D. and Koepf, E. K. and Grimes, J. and Jones, E. Y. and Stuart, D. I. and McLaughlin, P. J. and Robinson, R. C.}
}
@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 {3640,
	title = {Molecular mechanisms underlying the interaction of motuporin and microycystins with type-1 and type-2A protein phosphatases},
	journal = {Biochemistry and Cell Biology-Biochimie Et Biologie Cellulaire},
	volume = {74},
	number = {4},
	year = {1996},
	note = {ISI Document Delivery No.: VX367Times Cited: 61Cited Reference Count: 35},
	pages = {569-578},
	type = {Article},
	abstract = {Heptapeptide microcystin and pentapeptide motuporin (nodularin-V) are equipotent inhibitors of type-1 and type-2A protein phosphatase catalytic subunits (PP-1c and PP-2Ac). Herein we describe elucidation of the molecular mechanisms involved in the interaction of these structurally similar hepatotoxins with PP-1c/PP-2Ac and identification of an important functional difference between their mode of interaction with these enzymes. Microcystin-LR, microcystin-LA and microcystin-LL were found to interact with PP-2Ac and PP-1c by a two-step mechanism involving rapid binding and inactivation of the protein phosphatase (PPase) catalytic subunit, followed by a slower covalent interaction (within hours). Covalent adducts comprising PPase-toxin complexes were separated from free PPase by C-18 reverse-phase liquid chromatography, thus allowing the time course of covalent adduct formation to be quantitated. In contrast to microcystins, motuporin (nodularin-V) and nodularin-R were unable to form covalent complexes with either PP-1c or PP-2Ac even after 96 h incubation. Specific reduction of microcystin-LA to dihydromicrocystin-LA abolished the ability of the toxin to form a covalent adduct with PP-2Ac. Specific methyl esterification of the single Glu residue in microcystin-LR rendered this toxin inactive as a PPase inhibitor and abolished subsequent formation of a covalent adduct. Our data indicate that inactivation of PP-2Ac/PP-1c by microcystins precedes covalent modification of the PPases via a Michael addition reaction between a nucleophilic phosphatase residue and Mdha in the heptapeptide toxin. In contrast, following rapid inactivation of PP-2Ac/PP-1c by motuporin, the equivalent N-methyldehydrobutyrine residue in this toxin is unreactive and does not form a covalent bond with the PPases. These results are consistent with structural data for (i) the NMR solution structures of microcystin-LR and motuporin, which indicate a striking difference in the relative positions of their corresponding dehydroamino acids in the toxin peptide backbone, and (ii) X-ray crystallographic data on an inactive complex between PP-1c and microcystin-LR, which show a covalent bond between Cys-273 and the bound toxin.},
	keywords = {BLUE-GREEN-ALGAE, CATALYTIC SUBUNIT, cyanobacteria, IDENTIFICATION, MICROCYSTIN-LR, microcystins, motuporin, nodularin, OKADAIC ACID, PHOSPHORYLATION, POTENT INHIBITOR, PROTEIN, PROTEIN PHOSPHATASES, RAT-LIVER, TOXINS},
	isbn = {0829-8211},
	url = {<Go to ISI>://A1996VX36700017},
	author = {Craig, M. and Luu, H. A. and McCready, T. L. and Williams, D. and Andersen, R. J. and Holmes, C. F. B.}
}
@article {3720,
	title = {Multiple pathways for denaturation of horse plasma gelsolin},
	journal = {Biochemistry and Cell Biology-Biochimie Et Biologie Cellulaire},
	volume = {74},
	number = {1},
	year = {1996},
	note = {ISI Document Delivery No.: UE605Times Cited: 1Cited Reference Count: 38},
	pages = {101-107},
	type = {Article},
	abstract = {Gelsolin purified from horse plasma carries a surface charge distribution that greatly influences how the protein unfolds, aggregates, or precipitates as a function of temperature or concentration of chemical denaturant. Modification of gelsolin with fluorescein isothiocyanate replaces positive charges on amine groups with bulky, negatively charged fluorescein moieties. This postpones thermally induced precipitation by about 10 degrees C [Koepf, E.K., and Burtnick, L.D. 1993. Eur. J. Biochem. 212: 713-718]. Interaction with cations such as Ca2+ or guanidinium(+) also alters the surface charge on gelsolin. This affects the structure of the protein in solution, modifies the pathway for unfolding, and moderates the onset of precipitation induced by chemical denaturants or heat. Denaturation of gelsolin is not interpretable in terms of a simple two-state cooperative mechanism. The pathway to a denatured state and intermediate structures present along the way depend upon the agent used to unfold the protein.},
	keywords = {ACTIN-BINDING-SITES, calcium, chemical, circular dichroism, denaturation, FLUORESCEIN ISOTHIOCYANATE, gelsolin, PROTEIN, thermal},
	isbn = {0829-8211},
	url = {<Go to ISI>://A1996UE60500011},
	author = {Koepf, E. K. and Burtnick, L. D.}
}
@article {3437,
	title = {AQUEOUS 2-PHASE POLYMER SYSTEMS AS TOOLS FOR THE STUDY OF A RECOMBINANT SURFACE-EXPRESSED ESCHERICHIA-COLI HEMAGGLUTININ},
	journal = {Applied and Environmental Microbiology},
	volume = {61},
	number = {9},
	year = {1995},
	note = {ISI Document Delivery No.: RT798Times Cited: 5Cited Reference Count: 15},
	month = {Sep},
	pages = {3251-3255},
	type = {Article},
	abstract = {The surface expression of an integral membrane hemagglutinin, HRA1, cloned from Escherichia coli O9:H10:K99 in heterologous E. coli strains was studied by utilizing a variety of polyethylene glycol-dextran and dextran-Ficoll aqueous two-phase polymer systems. Bacteria containing plasmids that encoded the hemagglutinin were found to partition differently from both the host bacteria lacking the plasmid and the original hemagglutinating strain in several of these systems. By using molecular biological techniques, the origin of the partition difference was unambiguously correlated to the expression of HRA1, providing evidence independent of the agglutination phenotype that the protein was accessible to the surrounding milieu. It Was demonstrated by using bacterial partition in charge-sensitive systems that the agglutination event was not likely to be due to the presence of a nonspecific positively charged surface protein, as HRA1-expressing clones showed no less affinity for the relatively positive polyethylene glycol-rich upper phase than did control bacteria, This work demonstrates the utility of aqueous polymer two-phase systems for the study of surface-expressed recombinant proteins, due to the sensitivity of the systems and the presence of excellent controls (the host bacteria before plasmid introduction). In cloning and expression studies of surface-associated proteins, two-phase aqueous polymer systems could be used as an alternative to antibody production for the monitoring of surface expression, and these systems may give valuable information on the surface exposure of the protein.},
	keywords = {ANTIGEN, CLONING, PROTEIN, STRAINS},
	isbn = {0099-2240},
	url = {<Go to ISI>://A1995RT79800010},
	author = {Lutwyche, P. and Norrisjones, R. and Brooks, D. E.}
}
@article {3013,
	title = {THE CELLULOSE-BINDING DOMAIN OF ENDOGLUCANASE-A (CENA) FROM CELLULOMONAS-FIMI - EVIDENCE FOR THE INVOLVEMENT OF TRYPTOPHAN RESIDUES IN BINDING},
	journal = {Molecular Microbiology},
	volume = {11},
	number = {4},
	year = {1994},
	note = {ISI Document Delivery No.: MW536Times Cited: 96Cited Reference Count: 46},
	month = {Feb},
	pages = {747-755},
	type = {Article},
	abstract = {Cellulomonas fimi endo-beta-1-4-glucanase A (CenA) contains a discrete N-terminal cellulose-binding domain (CBDCenA). Related CBDs occur in at least 16 bacterial glycanases and are characterized by four highly conserved Trp residues, two of which correspond to W14 and W68 of CBDCenA. The adsorption of CBDCenA to crystalline cellulose was compared with that of two Trp mutants (W14A and W68A). The affinities of the mutant CBDs for cellulose were reduced by approximately 50- and 30-fold, respectively, relative to the wild type. Physical measurements indicated that the mutant CBDs fold normally. Fluorescence data indicated that W14 and W68 were exposed on the CBD, consistent with their participation in binding to cellobiosyl residues on the cellulose surface.},
	keywords = {BACTERIAL CELLULASE, CELLOBIOHYDROLASES, CLONING, DNA, FLUORESCENS SUBSP CELLULOSA, FUNCTIONAL DOMAINS, GENE, PROTEIN, SEQUENCE, THERMOMONOSPORA-FUSCA},
	isbn = {0950-382X},
	url = {<Go to ISI>://A1994MW53600013},
	author = {Din, N. and Forsythe, I. J. and Burtnick, L. D. and Gilkes, N. R. and Miller, R. C. and Warren, R. A. J. and Kilburn, D. G.}
}
@article {2845,
	title = {HORSE PLASMA GELSOLIN LABELED WITH FLUORESCEIN ISOTHIOCYANATE RESPONDS TO CALCIUM AND ACTIN},
	journal = {European Journal of Biochemistry},
	volume = {212},
	number = {3},
	year = {1993},
	note = {ISI Document Delivery No.: KT704Times Cited: 7Cited Reference Count: 26},
	month = {Mar},
	pages = {713-718},
	type = {Article},
	abstract = {Reaction between horse plasma gelsolin and fluorescein-5-isothiocyanate (FITC) resulted in incorporation of 4.8 +/- 0.6 fluorescein groups/gelsolin molecule. The sites of modification were not clustered in any one portion of the gelsolin polypeptide chain; all major peptides produced by proteolytic digestion with alpha-chymotrypsin exhibited a fluorescence characteristic of fluorescein. FITC-gelsolin has a peptide-backbone circular dichroism spectrum at 20-degrees-C that is indistinguishable from that of native gelsolin, but FITC-gelsolin is considerably more resistant than native gelsolin to thermally induced precipitation. FITC-gelsolin is fully able to carry out severing of F-actin filaments, the prime function of gelsolin in plasma. An opening up of the structure of gelsolin on binding Ca2+ is evident from an increased susceptibility of FITC-gelsolin to quenching by I-. Ca2+ dependence of the interaction between gelsolin and actin is evident in titrations both of intensity and polarization of the fluorescence of FITC-gelsolin solutions. A Ca2+-sensitive interaction between gelsolin and tropomyosin also is observed.},
	keywords = {BINDING DOMAIN, FILAMENTS, PROTEIN, TROPOMYOSIN},
	isbn = {0014-2956},
	url = {<Go to ISI>://A1993KT70400010},
	author = {Koepf, E. K. and Burtnick, L. D.}
}
@article {7284,
	title = {INTERACTION OF PLASMA GELSOLIN WITH TROPOMYOSIN},
	journal = {Febs Letters},
	volume = {309},
	number = {1},
	year = {1992},
	note = {ISI Document Delivery No.: JL068Times Cited: 20Cited Reference Count: 17},
	month = {Aug},
	pages = {56-58},
	type = {Article},
	abstract = {Horse plasma gelsolin labelled with benzophenone-4-isothiocyanate can be photochemically cross-linked to rabbit cardiac tropomyosin. The cross-linking proceeds with greater efficiency in calcium-containing buffers. Further evidence for interaction between these proteins is provided by retention of fluorescently labelled gelsolin on tropomyosin-agarose affinity columns and by the ability of tropomyosin to cause an increase in the fluorescence intensity of gelsolin labelled with fluorescein-5-isothiocyanate. Both of these effects require the presence of calcium ions.},
	keywords = {actin, FILAMENTS, gelsolin, MUSCLE, PROTEIN, TROPOMYOSIN},
	isbn = {0014-5793},
	url = {<Go to ISI>://A1992JL06800013},
	author = {Koepf, E. K. and Burtnick, L. D.}
}
@article {7358,
	title = {MONOMER AND EXCIMER FLUORESCENCE OF HORSE PLASMA GELSOLIN LABELED WITH N-(1-PYRENYL)IODOACETAMIDE},
	journal = {Biochemistry and Cell Biology-Biochimie Et Biologie Cellulaire},
	volume = {70},
	number = {7},
	year = {1992},
	note = {ISI Document Delivery No.: JP667Times Cited: 3Cited Reference Count: 27},
	month = {Jul},
	pages = {573-578},
	type = {Article},
	abstract = {Horse plasma gelsolin was labelled with the sulfhydryl-specific fluorescent reagent N-(1-pyrenyl)iodoacetamide. The level of incorporation of probe was 1.6 +/- 0.3 mol pyrene/mol gelsolin. The circular dichroism spectrum of pyrenyl-gelsolin and its ability to interact with muscle actin were not different from that found for unmodified gelsolin. The emission from pyrenyl-gelsolin was dominated by a broad emission band centred near 483 nm, characteristic of the presence of pyrene excimers. Analysis of excitation spectra for the monomer and excimer-type fluorescence suggested that ground-state interactions may occur between adjacent pyrenes in the gelsolin structure. In the case either of excimer formation or of ground-state pyrene-pyrene interactions in doubly labelled gelsolin molecules, the modified Cys residues must be in close proximity in the folded protein structure. Thermal denaturation of gelsolin could be monitored by observing the decrease in excimer emission that accompanied heating and unfolding of the tertiary structure. While heat treatment alone did not eliminate excimer fluorescence, digestion of gelsolin with chymotrypsin completely abolished such emission. Also, pyrenyl-gelsolin prepared and studied in 6 M guanidine-HCl exhibited fluorescence characteristic of pyrene monomers exclusively.},
	keywords = {ACTIN-FILAMENTS, BINDING, CIRCULAR-DICHROISM, denaturation, FLUORESCENCE LIFETIME, gelsolin, POLYMERIZATION, PROBE, PROTEIN, PYRENE EXCIMER FLUORESCENCE, PYRENE-ACTIN, STATE, thermal, TROPOMYOSIN},
	isbn = {0829-8211},
	url = {<Go to ISI>://A1992JP66700008},
	author = {Silva, B. E. R. and Koepf, E. K. and Burtnick, L. D. and Turro, N. J.}
}
@article {7110,
	title = {INTERACTION OF HORSE PLASMA GELSOLIN WITH THE HYDROPHOBIC FLUORESCENT-PROBE 2-(N-METHYLANILINO)NAPHTHALENE-6-SULFONIC ACID},
	journal = {Biochemistry International},
	volume = {23},
	number = {5},
	year = {1991},
	note = {ISI Document Delivery No.: FR334Times Cited: 2Cited Reference Count: 15},
	month = {Mar},
	pages = {905-913},
	type = {Article},
	keywords = {2-AMINONAPHTHALENE-6-SULFONATE, actin, BINDING, Electronic spectra, MOLECULES, PROTEIN},
	isbn = {0158-5231},
	url = {<Go to ISI>://A1991FR33400011},
	author = {Silva, B. E. R. and Burtnick, L. D. and Turro, N. J.}
}
