title: The folding pathway of spectrin R17 from experiment and simulation: using experimentally validated MD simulations to characterize States hinted at by experiment.
abstract: We present an experimental and computational analysis of the folding pathway of the 17th domain of chicken brain alpha-spectrin, R17. Wild-type R17 folds in a two-state manner and the chevron plot (plot of the logarithm of the observed rate constant against concentration of urea) shows essentially linear folding and unfolding arms. A number of mutant proteins, however, show a change in slope of the unfolding arm at high concentration of denaturant, hinting at complexity in the folding landscape. Through a combination of mutational studies and high temperature molecular dynamics simulations we show that the folding of R17 can be described by a model with two sequential transition states separated by an intermediate species. The rate limiting transition state for folding in water has been characterized both through experimental Phi-value analysis and by simulation. In contrast, a detailed analysis of the transition state predicted to dominate under highly denaturing conditions is only possible by simulation.
authors.affiliation: MRC Centre for Protein Engineering, University of Cambridge Chemical Laboratory, UK.
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Scott
authors.forename: Lucy G
authors.initials: LG
authors.lastname: Randles
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Moran
authors.forename: Valerie
authors.initials: V
authors.lastname: Daggett
authors.forename: Jane
authors.initials: J
authors.lastname: Clarke
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001923:Brain Chemistry; D002645:Chickens; D003198:Computer Simulation; D008958:Models, Molecular; D009154:Mutation; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D013049:Spectrin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D013049:Spectrin