title: Cooperative folding kinetics of BBL protein and peripheral subunit-binding domain homologues.
abstract: Recent experiments claiming that Naf-BBL protein follows a global downhill folding raised an important controversy as to the folding mechanism of fast-folding proteins. Under the global downhill folding scenario, not only do proteins undergo a gradual folding, but folding events along the continuous folding pathway also could be mapped out from the equilibrium denaturation experiment. Based on the exact calculation using a free energy landscape, relaxation eigenmodes from a master equation, and Monte Carlo simulation of an extended Muñoz-Eaton model that incorporates multiscale-heterogeneous pairwise interactions between amino acids, here we show that the very nature of a two-state cooperative transition such as a bimodal distribution from an exact free energy landscape and biphasic relaxation kinetics manifest in the thermodynamics and folding-unfolding kinetics of BBL and peripheral subunit-binding domain homologues. Our results provide an unequivocal resolution to the fundamental controversy related to the global downhill folding scheme, whose applicability to other proteins should be critically reexamined.
authors.affiliation: National Research Laboratory for Computational Proteomics and Biophysics, Department of Physics, Pusan National University, Busan 609-735, Korea.
authors.forename: Wookyung
authors.initials: W
authors.lastname: Yu
authors.forename: Kwanghoon
authors.initials: K
authors.lastname: Chung
authors.forename: Mookyung
authors.initials: M
authors.lastname: Cheon
authors.forename: Muyoung
authors.initials: M
authors.lastname: Heo
authors.forename: Kyou-Hoon
authors.initials: KH
authors.lastname: Han
authors.forename: Sihyun
authors.initials: S
authors.lastname: Ham
authors.forename: Iksoo
authors.initials: I
authors.lastname: Chang
mesh_terms: D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism*; D007700:Kinetics; D008954:Models, Biological; D011485:Protein Binding; D011489:Protein Denaturation; D017510:Protein Folding; D013696:Temperature; D013816:Thermodynamics
chemical_list: D029968:Escherichia coli Proteins