ROLE OF PHOSPHORYLATION AS A REGULATORY MECHANISM IN MUSCLE CONTRACTION

肌球蛋白磷酸化依赖的调控机制 对平滑肌和非肌球蛋白的研究正在进行中。这涉及到 几种方法：(1)测量不同步骤的速率常数 重链肌球蛋白(HMM)对镁三磷酸腺苷的水解动力学循环， 肌球蛋白的蛋白分解亚片段，在存在和不存在的情况下 肌动蛋白；(2)细胞质肌球蛋白HMM的制备及性质 它们的动力学特性；以及(3)使用体外运动系统 定量研究肌球蛋白包被珠的运动速度是如何受到影响的 受到各种因素的影响。我们也在研究它的作用机制。 Caldesmon，一种可能与肌动蛋白细丝相关的调节蛋白。

The mechanism of the phosphorylation-dependent myosin-linked regulation of smooth muscle and nonmuscle myosins is being investigated. This involves several approaches: (1) measurement of rate constants for various steps in the kinetic cycle for the hydrolysis of MgATP by heavy meromyosin (HMM), the proteolytic subfragment of myosin, in the presence and absence of actin; (2) preparation of HMM from cytoplasmic myosins and characterization of their kinetic properties; and (3) use of an in vitro motility system to quantitate how the velocity of movement of myosin-coated beads is affected by various factors. We are also studying the mechanism of action of caldesmon, a possible regulatory protein associated with actin filaments.