Effects of cardiac Myosin binding protein-C on actin motility are explained with a drag-activation-competition model

Biophys J. 2015 Jan 6;108(1):10-3. doi: 10.1016/j.bpj.2014.11.1852.


Although mutations in cardiac myosin binding protein-C (cMyBP-C) cause heart disease, its role in muscle contraction is not well understood. A mechanism remains elusive partly because the protein can have multiple effects, such as dual biphasic activation and inhibition observed in actin motility assays. Here we develop a mathematical model for the interaction of cMyBP-C with the contractile proteins actin and myosin and the regulatory protein tropomyosin. We use this model to show that a drag-activation-competition mechanism accurately describes actin motility measurements, while models lacking either drag or competition do not. These results suggest that complex effects can arise simply from cMyBP-C binding to actin.

Publication types

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

MeSH terms

  • Actins / metabolism*
  • Adenosine Triphosphate / metabolism
  • Calcium / metabolism
  • Carrier Proteins / metabolism*
  • Models, Molecular*
  • Motion
  • Myosins / metabolism*
  • Tropomyosin / metabolism*


  • Actins
  • Carrier Proteins
  • Tropomyosin
  • myosin-binding protein C
  • Adenosine Triphosphate
  • Myosins
  • Calcium