Millisecond time resolution electron cryo-microscopy of the M-ATP transient kinetic state of the acto-myosin ATPase

Biophys J. 1995 Apr;68(4 Suppl):87S-91S.

Abstract

The structure of the AM-ATP transient kinetic state of the acto-myosin ATPase cycle has been examined by electron microscopy using frozen-hydrated specimens prepared in low ionic strength. By spraying grids layered with the acto-S1 complex with ATP immediately before freezing, it was possible to examine the structure of the ternary complex with a time resolution of 10 ms. Disordered binding of the S1 was observed, suggesting more than one attachment geometry. This could be due to the presence of more than one biochemical intermediate, or to a single intermediate binding in more than one conformation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenosine Triphosphate / analogs & derivatives
  • Adenosine Triphosphate / metabolism*
  • Animals
  • Biophysical Phenomena
  • Biophysics
  • Freezing
  • Hydrolysis
  • In Vitro Techniques
  • Kinetics
  • Microscopy, Electron
  • Models, Biological
  • Muscle Contraction / physiology
  • Myosin Subfragments / metabolism
  • Myosin Subfragments / physiology
  • Myosin Subfragments / ultrastructure
  • Myosins / metabolism*
  • Myosins / physiology
  • Myosins / ultrastructure*
  • Osmolar Concentration
  • Swine
  • ortho-Aminobenzoates

Substances

  • Myosin Subfragments
  • ortho-Aminobenzoates
  • 3'-O-(N-methylanthraniloyl) ATP
  • Adenosine Triphosphate
  • Myosins