The hydrolysis activity of adenosine triphosphate in myosin: a theoretical analysis of anomeric effects and the nature of the transition state.

ABSTRACT: Combined quantum mechanical/molecular mechanical (QM/MM) calculations with density functional theory are employed to analyze two issues related to the hydrolysis activity of adenosine triphosphate (ATP) in myosin. First, we compare the geometrical properties and electronic structure of ATP in the open (post-rigor) and closed (pre-powerstroke) active sites of the myosin motor domain. Compared to both solution and the open active site cases, the scissile P(gamma)-O(3beta) bond of ATP in the closed active site is shown to be substantially elongated. Natural bond orbital (NBO) analysis clearly shows that this structural feature is correlated with the stronger anomeric effects in the closed active site, which involve charge transfers from the lone pairs in the nonbridging oxygen in the gamma-ph

SUBMITTER: Yang Y 

PROVIDER: S-EPMC2783400 | biostudies-literature | 2009 Nov

REPOSITORIES: biostudies-literature