Low folding cooperativity of HP35 revealed by single-molecule force spectroscopy and molecular dynamics simulation.

ABSTRACT: Some small proteins, such as HP35, fold at submicrosecond timescale with low folding cooperativity. Although these proteins have been extensively investigated, still relatively little is known about their folding mechanism. Here, using single-molecule force spectroscopy and steered molecule dynamics simulation, we study the unfolding of HP35 under external force. Our results show that HP35 unfolds at extremely low forces without a well-defined unfolding transition state. Subsequently, we probe the structure of unfolded HP35 using the persistence length obtained in the force spectroscopy. We found that the persistence length of unfolded HP35 is around 0.72 nm, >40% longer than typical unstructured proteins, suggesting that there are a significant amount of residual secondary structures in t

SUBMITTER: Lv C 

PROVIDER: S-EPMC3328709 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature