External release of entropy by synchronized movements of local secondary structures drives folding of a small, disulfide-bonded protein.

ABSTRACT: A crucial mechanism to the formation of native, fully functional, 3D structures from local secondary structures is unraveled in this study. Through the introduction of various amino acid substitutions at four canonical β-turns in a three-fingered protein, Toxin α from Naja nigricollis, we found that the release of internal entropy to the external environment through the globally synchronized movements of local substructures plays a crucial role. Throughout the folding process, the folding species were saturated with internal entropy so that intermediates accumulated at the equilibrium state. Their relief from the equilibrium state was accomplished by the formation of a critical disulfide bridge, which could guide the synchronized movement of one of the peripheral secondary structure. This

SUBMITTER: Sato A 

PROVIDER: S-EPMC5997310 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature