Multiple stepwise refolding of immunoglobulin domain I27 upon force quench depends on initial conditions.

ABSTRACT: Mechanical folding trajectories for polyproteins starting from initially stretched conformations generated by single-molecule atomic force microscopy experiments [Fernandez, J. M. & Li, H. (2004) Science 303, 1674-1678] show that refolding, monitored by the end-to-end distance, occurs in distinct multiple stages. To clarify the molecular nature of folding starting from stretched conformations, we have probed the folding dynamics, upon force quench, for the single I27 domain from the muscle protein titin by using a C(alpha)-Go model. Upon temperature quench, collapse and folding of I27 are synchronous. In contrast, refolding from stretched initial structures not only increases the folding and collapse time scales but also decouples the two kinetic processes. The increase in the folding time

SUBMITTER: Li MS 

PROVIDER: S-EPMC1324974 | biostudies-literature | 2006 Jan

REPOSITORIES: biostudies-literature