肌动蛋白-H-肌球蛋白ATP酶反应对于动脉平滑肌的基本步骤。

Elementary steps in the acto-H-meromyosin ATPase reaction to arterial smooth muscle.

作者信息

Takeuchi K, Tonomura Y

出版信息

J Biochem. 1978 Aug;84(2):285-92. doi: 10.1093/oxfordjournals.jbchem.a132129.

DOI:10.1093/oxfordjournals.jbchem.a132129

Abstract

Transient and steady state kinetics were studied in the interactions of ATP with acto-H-meromyosin reconstituted from bovine arterial heavy-meromyosin (HMM) and rabbit skeletal muscle F-actin. The results showed that the rate of dissociation of the hybrid acto-HMM induced by ATP was slower than the rate of the fluorescence enhancement of HMM, and that the rate of the P1 burst of HMM was unaffected by addition of skeletal muscle F-actin. The ATPase [EC 3.6.1.3] activity of arterial HMM was activated only slightly even with addition of high concentrations of skeletal muscle F-actin. Furthermore, the rates of dissociation of the hybrid acto-HMM induced by ATP and reassociation of dissociated arterial HMM with skeletal muscle F-actin after decomposition of ATP were much lower than those of skeletal muscle acto-HMM.

摘要

研究了ATP与由牛动脉重链肌球蛋白（HMM）和兔骨骼肌F-肌动蛋白重构的肌动蛋白-H-肌球蛋白相互作用中的瞬态和稳态动力学。结果表明，ATP诱导的杂交肌动蛋白-HMM的解离速率比HMM的荧光增强速率慢，并且HMM的P1爆发速率不受骨骼肌F-肌动蛋白添加的影响。即使添加高浓度的骨骼肌F-肌动蛋白，动脉HMM的ATP酶[EC 3.6.1.3]活性也仅略有激活。此外，ATP诱导的杂交肌动蛋白-HMM的解离速率以及ATP分解后解离的动脉HMM与骨骼肌F-肌动蛋白的重新结合速率远低于骨骼肌肌动蛋白-HMM的解离速率和重新结合速率。