@article {2649,
	title = {Free Energy Barrier Estimation for the Dissociation of Charged Protein Complexes in the Gas Phase},
	journal = {Journal of Physical Chemistry A},
	volume = {113},
	number = {16},
	year = {2009},
	note = {ISI Document Delivery No.: 435ZUTimes Cited: 4Cited Reference Count: 29Wanasundara, Surajith N. Thachuk, Mark},
	month = {Apr},
	pages = {3814-3821},
	type = {Article},
	abstract = {Free energies are calculated for the protonated cytochrome c{\textquoteright} dimer ion in the gas phase as a function of the center of mass distance between the monomers. A number of different charge partitionings are examined as well as the behavior of the neutral complex. It is found that monomer unfolding competes with complex dissociation and that the relative importance of these two factors depends upon the charge partitioning in the complex. Symmetric charge partitionings preferentially suppress the dissociation barrier relative to unfolding, and complexes tend to dissociate promptly with little structural changes occurring in the monomers. Alternatively, asymmetric charge partitionings preferentially lower the barrier for monomer unfolding relative to the dissociation barrier. In this case, the monomer with the higher charge unfolds before the complex dissociates. For the homodimer considered here, this pathway has a large free energy barrier. The results can be rationalized using schematic two-dimensional free energy surfaces. Additionally, for large multimeric complexes, it is argued that the unfolding and subsequent charging of a single monomer is a favorable process, cooperatively lowering both the unfolding and dissociation barriers at the same time.},
	keywords = {ASSEMBLIES, ELECTROSPRAY-IONIZATION, MASS-SPECTROMETRY, MODEL, MOLECULAR-DYNAMICS, ORIGIN, PATHWAYS, SIMULATIONS, SYSTEMS, THERMAL-DISSOCIATION},
	isbn = {1089-5639},
	url = {<Go to ISI>://000265383200014},
	author = {Wanasundara, S. N. and Thachuk, M.}
}
@article {2175,
	title = {Gas-phase proton-transfer pathways in protonated histidylglycine},
	journal = {Rapid Communications in Mass Spectrometry},
	volume = {22},
	number = {18},
	year = {2008},
	note = {ISI Document Delivery No.: 355WATimes Cited: 2Cited Reference Count: 23MacDonald, Brandon I. Thachuk, Mark},
	month = {Sep},
	pages = {2946-2954},
	type = {Article},
	abstract = {Pathways for proton transfer in the histidylglycine cation are examined in the gas-phase environment with the goal of understanding the mechanism by which protons may become mobile in proteins with basic amino acid residues. An extensive search of the potential energy surface is performed using density functional theory (DFT) methods. After corrections for zero-point energy are included, it is found that all the lowest energy barriers for proton transfer between the N-terminus and the imidazole ring have heights of only a few kcal/mol, while those between the imidazole ring and the backbone amide oxygen have heights of approximately 15 kcal/mol when the proton is moving from the ring to the backbone and only a few kcal/mol when moving from the backbone to the imidazole ring. In mass spectrometric techniques employing collision-induced dissociation to dissociate protein complex ions or to fragment peptides, these barriers can be overcome, and the protons mobilized. Copyright (C) 2008 John Wiley \& Sons, Ltd.},
	keywords = {COLLISION-INDUCED DISSOCIATION, fragmentation, IONIZATION, MASS-SPECTROMETRY, mobility, MODEL, ORIGIN, PEPTIDE IONS},
	isbn = {0951-4198},
	url = {<Go to ISI>://000259738700023},
	author = {MacDonald, B. I. and Thachuk, M.}
}
@article {827,
	title = {Using ellipsoids to model charge distributions in gas phase protein complex ion dissociation},
	journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie},
	volume = {82},
	number = {12},
	year = {2004},
	note = {ISI Document Delivery No.: 898JHTimes Cited: 12Cited Reference Count: 31},
	month = {Dec},
	pages = {1736-1744},
	type = {Article},
	abstract = {Gas phase protein complex dissociation was modelled using ellipsoids on which discrete charges were placed in randomly chosen charge sites. A number of sizes, shapes, orientations, and types of ellipsoids were considered. For each case, charge transfer parameters and electrostatic energies were calculated as a function of the fractional surface area. It was found that to within 10-15\%, the charge on product ions after dissociation is distributed according to their fractional surface area. This can imply, for example, that in experiments measuring the dissociation of homodimers, charge asymmetries of greater than 10-15\% in the product ions signal that one of the ions has greatly increased its surface area, such as would occur with unfolding. This assumes that proton transfer occurs on a timescale fast enough that the dissociation products adopt the minimum electrostatic energy configuration. Calculation of this energy shows that it is minimized when one or more of the monomers is in an extended conformation.},
	keywords = {charge asymmetry, CYTOCHROME-C, ELECTROSPRAY-IONIZATION, ellipsoid charge model, EXCHANGE, IONIZATION MASS-SPECTROMETRY, ORIGIN, protein complex dissociation},
	isbn = {0008-4042},
	url = {<Go to ISI>://000227072600011},
	author = {Csiszar, S. and Thachuk, M.}
}
@article {338,
	title = {De Novo terpenoid biosynthesis by the dendronotid nudibranch Melibe leonina},
	journal = {Chemoecology},
	volume = {12},
	number = {4},
	year = {2002},
	note = {ISI Document Delivery No.: 635GATimes Cited: 6Cited Reference Count: 23},
	pages = {199-202},
	type = {Article},
	abstract = {Stable isotope feeding studies using [1,2-C-13(2)]-sodium acetate have demonstrated that 2,6-dimetbyl-5-heptenal (1), a putative defensive allomone, is made by the Dendronotid nudibranch Melibe leonina via de novo biosynthesis.},
	keywords = {biosynthesis, CADLINA-LUTEOMARGINATA, chemical, CHEMICAL DEFENSE, defense nudibranch, DORID-NUDIBRANCHS, ECOLOGY, ISOTOPE INCORPORATION EVIDENCE, OPISTHOBRANCH MOLLUSK, ORIGIN, terpenoid, TRIOPHAMINE},
	isbn = {0937-7409},
	url = {<Go to ISI>://000180389600006},
	author = {Barsby, T. and Linington, R. G. and Andersen, R. J.}
}
@article {4586,
	title = {Arsenic in the Meager Creek hot springs environment, British Columbia, Canada},
	journal = {Science of the Total Environment},
	volume = {236},
	number = {1-3},
	year = {1999},
	note = {ISI Document Delivery No.: 243EGTimes Cited: 66Cited Reference Count: 59},
	month = {Sep},
	pages = {101-117},
	type = {Article},
	abstract = {Levels of arsenic in water from Meager Creek hot springs, British Columbia, Canada, were found to be naturally elevated. Biota including microbial mats, green algae, sedge, cedar, fleabane, monkey flower, moss, mushrooms and lichens, that were expected to be impacted by the water, were analyzed for total levels of arsenic and for arsenic species. The major arsenic species extracted from all samples were arsenate and arsenite, which are toxic forms of arsenic. Additionally, small amounts of arsenosugars X and XI were detected in microbial mats and green algae, implying that cyanobacteria/bacteria, and possibly green algae are capable of synthesizing arsenosugars from arsenate. Low to trace amounts of arsenosugars X and XI were detected in lichens and the fungus Tarzetta cupularis. A large fraction (on average, greater than 50\%) of arsenic was not extracted by using methanol/water (1:1) and the chemical and toxicological significance of this arsenic remains unknown. (C) 1999 Elsevier Science B.V. All rights reserved.},
	keywords = {ALGA, arsenic, BIOACCUMULATION, BIOMETHYLATION, ESTUARINE WATERS, FATE, fungi, hot springs, microbial mats, ORGANISMS, ORIGIN, PLANTS, SPECIATION, WATER FOOD-CHAIN},
	isbn = {0048-9697},
	url = {<Go to ISI>://000082983600008},
	author = {Koch, I. and Feldmann, J. and Wang, L. X. and Andrewes, P. and Reimer, K. J. and Cullen, W. R.}
}
