[心脏线粒体和肌原纤维中肌酸磷酸激酶反应的功能特性]

[Functional characterization of the creatine phosphokinase reactions in heart mitochondria and myofibrils].

作者信息

Saks V A, Lipina N V, Liulina I V, Chernousova G B, Fetter R, Smirnov V I, Chazov E I

出版信息

Biokhimiia. 1976 Aug;41(8):1460-70.

Abstract

The kinetic properties of MM-isozyme of creatine phosphokinase (CPK) bound to heart myofibrils have been determined experimentally. It has been shown that CPK isozymes bound to the heart myofibrils and mitochondria are electrophoretically different, but have very similar kinetic properties. For both isozymes the ATP formation reaction is preferable. However, in heart mitochondria the kinetic properties of CPK are compensated for by a tight functional coupling with ATP-ADP translocase. Due to this coupling the ATP formed in the course of oxidative phosphorylation can be used completely for creatine phosphate production in mitochondria. On the other hand, the kinetic properties of myofibrillar CPK isozyme are such that they provide for the effective utilization of creatine phosphate produced in mitochondria for rephosphorylation of AKP formed in the myofibrils during contraction. It is concluded that in the heart cells energy can be transferred from the mitochondria to the myofibrils by creatine phosphate molecules.

摘要

已通过实验测定了与心肌肌原纤维结合的肌酸磷酸激酶（CPK）MM同工酶的动力学特性。结果表明，与心肌肌原纤维和线粒体结合的CPK同工酶在电泳上存在差异，但具有非常相似的动力学特性。对于这两种同工酶而言，ATP生成反应更占优势。然而，在心肌线粒体中，CPK的动力学特性通过与ATP-ADP转位酶的紧密功能偶联得到补偿。由于这种偶联，氧化磷酸化过程中形成的ATP可完全用于线粒体中磷酸肌酸的生成。另一方面，肌原纤维CPK同工酶的动力学特性使其能够有效利用线粒体中产生的磷酸肌酸，用于收缩过程中肌原纤维中形成的AKP的再磷酸化。得出的结论是，在心脏细胞中，能量可通过磷酸肌酸分子从线粒体转移至肌原纤维。