Effect of calponin on actin-activated myosin ATPase activity |
| |
Authors: | M Abe K Takahashi K Hiwada |
| |
Affiliation: | Second Department of Internal Medicine, Ehime University School of Medicine. |
| |
Abstract: | Calponin inhibited the actin-activated myosin MgATPase activity in a dose-dependent manner without affecting the phosphorylation level of myosin light chain. This inhibition was Ca2(+)-independent. The decrease in enzymatic activity of myosin was correlated with binding of calponin to actin-tropomyosin filaments. Caldesmon showed a further inhibition of the calponin-induced inhibition of MgATPase activity of the thiophosphorylated myosin. Calponin-induced inhibition of the myosin MgATPase activity was reversed by the addition of calmodulin only in the presence of Ca2+. These results suggest that calponin acts as an inhibitory component of smooth muscle thin filaments. |
| |
Keywords: | |
|