EFFECT OF CALPONIN ON ACTIN-ACTIVATED MYOSIN ATPASE ACTIVITY
EFFECT OF CALPONIN ON ACTIN-ACTIVATED MYOSIN ATPASE ACTIVITY
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DOI：
10.1093/oxfordjournals.jbchem.a123289
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发表时间：
1990-11-01
影响因子：
2.7
通讯作者：
HIWADA, K
中科院分区：
文献类型：
--
作者：
ABE, M;TAKAHASHI, K;HIWADA, K
Calponin 以剂量依赖性方式抑制肌动蛋白激活的肌球蛋白 MgATP 酶活性，而不影响肌球蛋白轻链的磷酸化水平。这种抑制不依赖于 Ca2+。肌球蛋白酶活性的降低与钙调蛋白与肌动蛋白原肌球蛋白丝的结合相关。 Caldesmon 显示出对硫代磷酸化肌球蛋白的 MgATP 酶活性的钙调蛋白诱导的抑制的进一步抑制。只有在存在 Ca2+ 的情况下，添加钙调蛋白才能逆转钙调蛋白诱导的肌球蛋白 MgATP 酶活性抑制。这些结果表明钙调蛋白充当平滑肌细丝的抑制成分。
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-inuced 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.