Effect of C-protein on actomyosin ATPase

Biochim Biophys Acta. 1980 Oct 1;632(2):141-9. doi: 10.1016/0304-4165(80)90071-9.

Abstract

The effect of C-protein on the actin-activated ATPase of column-purified skeletal muscle myosin has been investigated at varied ionic strength. At ionic strengths below about 0.1, C-protein is a potent inhibitor. The inhibition is not reversed by increasing the actin concentration, showing that it is caused by C-protein bound to the myosin filaments. When the ionic strength is raised above about 0.12, on the other hand, the inhibition vanishes and C-protein becomes a mild activator of the actomyosin ATPase. Both effects appear rapidly upon addition of C-protein to pre-formed myosin filaments, so C-protein probably acts by binding to the surface of the filaments.

Publication types

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

MeSH terms

  • Actins / pharmacology
  • Actomyosin / metabolism*
  • Adenosine Triphosphatases / antagonists & inhibitors
  • Adenosine Triphosphatases / metabolism*
  • Animals
  • Carrier Proteins
  • Dose-Response Relationship, Drug
  • Enzyme Activation
  • Muscle Proteins / pharmacology*
  • Muscles / enzymology
  • Myosins / metabolism
  • Protein Binding
  • Rabbits

Substances

  • Actins
  • Carrier Proteins
  • Muscle Proteins
  • myosin-binding protein C
  • Actomyosin
  • Adenosine Triphosphatases
  • Myosins