Myosin-binding protein C phosphorylation, myofibril structure, and contractile function during low-flow ischemia
Myosin-binding protein C phosphorylation, myofibril structure, and contractile function during low-flow ischemia
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DOI：
10.1161/01.cir.0000155609.95618.75
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发表时间：
2005-02-22
期刊：
影响因子：
37.8
通讯作者：
Winegrad, S
中科院分区：
文献类型：
--
作者：
Decker, RS;Decker, ML;Winegrad, S
背景-在低流量缺血发作后，长期仪器化的犬心肌会出现收缩功能障碍，并在再灌注后持续存在。本研究的目的是确定肌球蛋白结合蛋白 C (MyBP-C) 磷酸化状态的变化是否是功能障碍的潜在原因。方法和结果 - 在低流量缺血期间，MyBP-C 去磷酸化，并且随着粗肌丝从肌原纤维外围分解，肌节中央核心的肌动球蛋白跨桥数量减少。再灌注期间，MyBP-C 保持去磷酸化，并且其降解加速。结论 - MyBP-C 去磷酸化可能引发肌原纤维粗丝结构的变化，从而减少肌球蛋白头与肌动蛋白细丝的相互作用。限制肌动球蛋白跨桥的形成可能导致低流量缺血后明显的收缩功能障碍。再灌注期间 MyBP-C 的分解可能会延长心肌顿抑时间。
Background - Contractile dysfunction develops in the chronically instrumented canine myocardium after bouts of low-flow ischemia and persists after reperfusion. The objective of this study is to identify whether changes in the phosphorylation state of myosin-binding protein C (MyBP-C) are a potential cause of dysfunction.Methods and Results - During low-flow ischemia, MyBP-C is dephosphorylated, and the number of actomyosin cross-bridges in the central core of the sarcomere decreases as thick filaments dissemble from the periphery of the myofibril. During reperfusion, MyBP-C remains dephosphorylated, and its degradation is accelerated.Conclusions - Dephosphorylation of MyBP-C may initiate changes in myofibril thick filament structure that decrease the interaction of myosin heads with actin thin filaments. Limiting the formation of actomyosin cross-bridges may contribute to the contractile dysfunction that is apparent after low-flow ischemia. Breakdown of MyBP-C during reperfusion may prolong myocardial stunning.