Nanosecond motions in proteins impose bounds on the timescale distributions of local dynamics.

ABSTRACT: We elucidate the physics of protein dynamical transition via 10-100-ns molecular dynamics simulations at temperatures spanning 160-300 K. By tracking the energy fluctuations, we show that the protein dynamical transition is marked by a crossover from nonstationary to stationary processes that underlie the dynamics of protein motions. A two-timescale function captures the nonexponential character of backbone structural relaxations. One timescale is attributed to the collective segmental motions and the other to local relaxations. The former is well defined by a single-exponential, nanosecond decay, operative at all temperatures. The latter is described by a set of processes that display a distribution of timescales. Although their average remains on the picosecond timescale, the distributio

SUBMITTER: Okan OB 

PROVIDER: S-EPMC2756386 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature