title: Protein folding stabilizing time measurement: a direct folding process and three-dimensional random walk simulation.
abstract: Protein particles undergo Brownian motion and collisions in solution. The diffusive collisions may lead to aggregation. For proteins to fold successfully the process has to occur quickly and before significant collision takes place. The speed of protein folding was deduced by studying the correlation time of a lysozyme refolding process from autocorrelation function analysis of the mean collision time and aggregation/soluble ratio of protein. It is a measure of time before which an aggregate can be formed and also is the time measure for a protein to fold into a stable state. We report on the protein folding stabilizing time of a lysozyme system to be 25.5-27.5 micros (<+/-4%) between 295 and 279K via direct folding experimental studies, supported by a three-dimensional random walk simulation of diffusion-limited aggregation model. Aggregation is suppressed when the protein is folded to a stable form. Spontaneous folding and diffusion-limited aggregation are antagonistic in nature. Meanwhile, the resultant aggresome, suggested by Raman and mass spectroscopy, may be formed by cross-linkages of disulfide bonds and hydrophobic interactions.
authors.affiliation: Department of Physics, National Dong Hwa University, Hualien 97401, Taiwan. chiaching@mail.ndhu.edu.tw
authors.forename: Chia-Ching
authors.initials: CC
authors.lastname: Chang
authors.forename: Po-Yen
authors.initials: PY
authors.lastname: Lin
authors.forename: Xu-Cheng
authors.initials: XC
authors.lastname: Yeh
authors.forename: Kuang-Hau
authors.initials: KH
authors.lastname: Deng
authors.forename: Yen-Peng
authors.initials: YP
authors.lastname: Ho
authors.forename: Lou-Sing
authors.initials: LS
authors.lastname: Kan
mesh_terms: D001665:Binding Sites; D003198:Computer Simulation; D004058:Diffusion; D004795:Enzyme Stability; D007700:Kinetics; D008956:Models, Chemical; D015233:Models, Statistical; D046912:Multiprotein Complexes / Q000032:analysis / Q000737:chemistry; D009113:Muramidase / Q000032:analysis* / Q000737:chemistry*; D011485:Protein Binding; D017510:Protein Folding; D011506:Proteins / Q000032:analysis* / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D013059:Spectrum Analysis, Raman / Q000379:methods
chemical_list: D046912:Multiprotein Complexes; D011506:Proteins; D009113:Muramidase