大鼠肌肉AMP脱氨酶与肌球蛋白的相互作用。II. 肌球蛋白对大鼠肌肉AMP脱氨酶动力学和调节特性的修饰。

Interaction of rat muscle AMP deaminase with myosin. II. Modification of the kinetic and regulatory properties of rat muscle AMP deaminase by myosin.

作者信息

Shiraki H, Ogawa H, Matsuda Y, Nakagawa H

出版信息

Biochim Biophys Acta. 1979 Feb 9;566(2):345-52. doi: 10.1016/0005-2744(79)90038-x.

PMID:420860

Abstract

The problems of whether the kinetic and regulatory properties of AMP deaminase were modified by formation of a deaminase-myosin complex were investigated with an enzyme preparation from rat skeletal muscle. Results showed that AMP deaminase was activated by binding to myosin. Myosin-bound AMP deaminase showed a sigmoidal activity curve with respect to AMP concentration in the absence of ATP and ADP, but a hyperbolic curve in their presence. Addition of ATP and ADP doubled the V value, but did not affect the Km value. Myosin-bound AMP deaminase also gave a sigmoidal curve in the presence of alkali metal ions, whereas free AMP deaminase gave a hyperbolic curve. GTP abolished the activating effects of both myosin and ATP.

摘要

利用大鼠骨骼肌的酶制剂，研究了AMP脱氨酶的动力学和调节特性是否因脱氨酶-肌球蛋白复合物的形成而改变。结果表明，AMP脱氨酶通过与肌球蛋白结合而被激活。在没有ATP和ADP的情况下，与肌球蛋白结合的AMP脱氨酶相对于AMP浓度呈现S形活性曲线，但在有ATP和ADP存在时呈现双曲线。添加ATP和ADP使V值加倍，但不影响Km值。在碱金属离子存在下，与肌球蛋白结合的AMP脱氨酶也呈现S形曲线，而游离的AMP脱氨酶呈现双曲线。GTP消除了肌球蛋白和ATP的激活作用。