A dynamic approach reveals non-muscle myosin influences the overall smooth muscle cross-bridge cycling rate

FEBS Lett. 2010 Jul 2;584(13):2862-6. doi: 10.1016/j.febslet.2010.04.070. Epub 2010 May 4.


Recent evidence suggests that non-muscle myosin IIB (NMIIB) contributes to smooth muscle contraction. This study was designed to determine the effects of NMIIB on the cross-bridge cycling rate. The cross-bridge cycling rate was investigated using sinusoidal analysis. Frequency analysis revealed two asymptotes in the Bode plot of the data; and the intersection of the asymptotes (corner frequency) was higher for the B(+/-) strain (8.73+/-1.10 Hz vs 16.56+/-1.26 Hz, P<0.05), consistent with a higher overall cross-bridge cycling rate in heterozygous NMIIB KO (B(+/-)) vs WT mice. These results demonstrate that because of their long duty cycle, NMIIB cross-bridges act as an internal load on smooth muscle myosin to decrease the overall cross-bridge cycling rate and muscle V(max) during force maintenance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • In Vitro Techniques
  • Mice
  • Muscle Contraction / physiology*
  • Muscle, Smooth / metabolism*
  • Muscle, Smooth / physiology*
  • Myosins / metabolism*
  • Temperature


  • Myosins