Native topology determines force-induced unfolding pathways in globular proteins.

ABSTRACT: Single-molecule manipulation techniques reveal that stretching unravels individually folded domains in the muscle protein titin and the extracellular matrix protein tenascin. These elastic proteins contain tandem repeats of folded domains with beta-sandwich architecture. Herein, we propose by stretching two model sequences (S1 and S2) with four-stranded beta-barrel topology that unfolding forces and pathways in folded domains can be predicted by using only the structure of the native state. Thermal refolding of S1 and S2 in the absence of force proceeds in an all-or-none fashion. In contrast, phase diagrams in the force-temperature (f,T) plane and steered Langevin dynamics studies of these sequences, which differ in the native registry of the strands, show that S1 unfolds in an allor-none

SUBMITTER: Klimov DK 

PROVIDER: S-EPMC16532 | biostudies-literature | 2000 Jun

REPOSITORIES: biostudies-literature