title: Modulation of contact order effects in the two-state folding of stefins A and B.
abstract: It is well established that contact order and folding rates are correlated for small proteins. The folding rates of stefins A and B differ by nearly two orders of magnitude despite sharing an identical native fold and hence contact order. We break down the determinants of this behavior and demonstrate that the modulation of contact order effects can be accounted for by the combined contributions of a framework-like mechanism, characterized by intrinsic helix stabilities, together with nonnative helical backbone conformation and nonnative hydrophobic interactions within the folding transition state. These contributions result in the formation of nonnative interactions in the transition state as evidenced by the opposing effects on folding rate and stability of these proteins.
authors.affiliation: Department of Molecular Biology and Biotechnology, Krebs Institute, Western Bank, University of Sheffield, Sheffield, United Kingdom.
authors.forename: Clare
authors.initials: C
authors.lastname: Jelinska
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Davis
authors.forename: Manca
authors.initials: M
authors.lastname: Kenig
authors.forename: Eva
authors.initials: E
authors.lastname: Zerovnik
authors.forename: Saša Jenko
authors.initials: SJ
authors.lastname: Kokalj
authors.forename: Gregor
authors.initials: G
authors.lastname: Gunčar
authors.forename: Dušan
authors.initials: D
authors.lastname: Turk
authors.forename: Vito
authors.initials: V
authors.lastname: Turk
authors.forename: David T
authors.initials: DT
authors.lastname: Clarke
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Waltho
authors.forename: Rosemary A
authors.initials: RA
authors.lastname: Staniforth
mesh_terms: D000595:Amino Acid Sequence; D015891:Cystatins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D018698:Glutamic Acid / Q000235:genetics; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D017354:Point Mutation / Q000235:genetics; D011110:Polymorphism, Genetic; D017510:Protein Folding; D055550:Protein Stability; D017433:Protein Structure, Secondary; D013816:Thermodynamics; D014443:Tyrosine / Q000235:genetics
chemical_list: D015891:Cystatins; D010455:Peptides; D018698:Glutamic Acid; D014443:Tyrosine