MUSCLE-CONTRACTION AND FREE-ENERGY TRANSDUCTION IN BIOLOGICAL-SYSTEMS
MUSCLE-CONTRACTION AND FREE-ENERGY TRANSDUCTION IN BIOLOGICAL-SYSTEMS
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DOI：
10.1126/science.3156404
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发表时间：
1985-01-01
期刊：
影响因子：
56.9
通讯作者：
HILL, TL
中科院分区：
文献类型：
--
作者：
EISENBERG, E;HILL, TL
当肌肉中的肌动蛋白和肌球蛋白细丝在三磷酸腺苷(ATP)和肌动蛋白与从肌球蛋白延伸出来的横桥的循环作用下相互作用时，肌肉就会收缩。目前的生化研究表明，在每个腺苷三磷酸酶周期中，肌球蛋白在两种主要构象之间交替，这两种构象与肌动蛋白的结合强度和整体结构明显不同。ATP与交叉桥的结合诱导了弱结合构象，而无机磷的释放使交叉桥返回到强结合构象。这种跨桥循环类似于驱动主动转运的动力学循环，并说明了三磷酸腺苷系统自由能转导的一般原理。
Muscle contraction occurs when the actin and myosin filaments in muscle are driven past each other by a cyclic interaction of adenosine triphosphate (ATP) and actin with cross-bridges that extend from myosin. Current biochemical studies suggest that, during each adenosine triphosphatase cycle, the myosin cross-bridge alternates between two main conformations, which differ markedly in their strength of binding to actin and in their overall structure. Binding of ATP to the cross-bridge induces the weak-binding conformation, whereas inorganic phosphate release returns the cross-bridge to the strong-binding conformation. This cross-bridge cycle is similar to the kinetic cycle that drives active transport and illustrates the general principles of free energy transduction by adenosine triphosphatase systems.