@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 = {://000265383200014}, author = {Wanasundara, S. N. and Thachuk, M.} } @article {800, title = {Yeast genome-wide drug-induced haploinsufficiency screen to determine drug mode of action}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {101}, number = {13}, year = {2004}, note = {ISI Document Delivery No.: 809PNTimes Cited: 73Cited Reference Count: 23}, month = {Mar}, pages = {4525-4530}, type = {Article}, abstract = {Methods to systematically test drugs against all possible proteins in a cell are needed to identify the targets underlying their therapeutic action and unwanted effects. Here, we show that a genome-wide drug-induced haploinsufficiency screen by using yeast can reveal drug mode of action in yeast and can be used to predict drug mode of action in human cells. We demonstrate that dihydromotuporamine C, a compound in preclinical development that inhibits angiogenesis and metastasis by an unknown mechanism, targets sphingolipid metabolism. The systematic, unbiased and genome-wide nature of this technique makes it attractive as a general approach to identify cellular pathways affected by drugs.}, keywords = {DELETION, GENE, INVASION, MUTANT, PATHWAYS, PDK1, SACCHAROMYCES-CEREVISIAE, SUPPRESSORS}, isbn = {0027-8424}, url = {://000220648700037}, author = {Baetz, K. and McHardy, L. and Gable, K. and Tarling, T. and Reberioux, D. and Bryan, J. and Andersen, R. J. and Dunn, T. and Hieter, P. and Roberge, M.} } @article {4028, title = {Cytochrome c folding kinetics studied by time-resolved electrospray ionization mass spectrometry}, journal = {Biochemistry}, volume = {36}, number = {18}, year = {1997}, note = {ISI Document Delivery No.: WY063Times Cited: 82Cited Reference Count: 46}, month = {May}, pages = {5554-5559}, type = {Article}, abstract = {A new method for studying the folding kinetics of proteins is described. The method combines a continuous flow mixing technique with an electrospray mass spectrometer. Different protein conformations in solution are detected by the different charge states they produce during electrospray ionization. Unfolded proteins generally have more accessible protonation sites and give higher charge states than native proteins. The method is applied to study the refolding of acid-denatured cytochrome c. Global data analysis is used to obtain the exponential lifetimes which are associated with the refolding process. The kinetics can be described by two lifetimes of 0.17 +/- 0.02 and 8.1 +/- 0.9 s which are in accordance with the results of stopped flow experiments previously described in the literature. These lifetimes are associated with roughly 90 and 10\% of the total intensity changes in the mass spectrum, respectively, and most likely reflect fast and slow refolding subpopulations of cytochrome c in solution.}, keywords = {COMPLEX, denaturation, FERRICYTOCHROME-C, IRON BLEOMYCIN, LIGANDS, MECHANISM, PATHWAYS, PROBING CONFORMATIONAL-CHANGES, PROTEINS, SPECTRA}, isbn = {0006-2960}, url = {://A1997WY06300029}, author = {Konermann, L. and Collings, B. A. and Douglas, D. J.} }