Direct real-time detection of the structural and biochemical events in the myosin power stroke.

ABSTRACT: A principal goal of molecular biophysics is to show how protein structural transitions explain physiology. We have developed a strategic tool, transient time-resolved FRET [(TR)(2)FRET], for this purpose and use it here to measure directly, with millisecond resolution, the structural and biochemical kinetics of muscle myosin and to determine directly how myosin's power stroke is coupled to the thermodynamic drive for force generation, actin-activated phosphate release, and the weak-to-strong actin-binding transition. We find that actin initiates the power stroke before phosphate dissociation and not after, as many models propose. This result supports a model for muscle contraction in which power output and efficiency are tuned by the distribution of myosin structural states. This technolog

SUBMITTER: Muretta JM 

PROVIDER: S-EPMC4655543 | biostudies-literature | 2015 Nov

REPOSITORIES: biostudies-literature