Wallimann T, Walzthöny D, Wegmann G, Moser H, Eppenberger H M, Barrantes F J
J Cell Biol. 1985 Apr;100(4):1063-72. doi: 10.1083/jcb.100.4.1063.
Creatine kinase (CK, EC 2.7.3.2) has recently been identified as the intermediate isoelectric point species (pl 6.5-6.8) of the Mr 40,000-43,000 nonreceptor, peripheral v-proteins in Torpedo marmorata acetylcholine receptor-rich membranes (Barrantes, F. J., G. Mieskes, and T. Wallimann, 1983, Proc. Natl. Acad. Sci. USA, 80: 5440-5444). In the present study, this finding is substantiated at the cellular and subcellular level of the T. marmorata electric organ by immunofluorescence and by protein A-gold labeling of either ultrathin cryosections of electrocytes or purified receptor-membrane vesicles that use subunit-specific anti-chicken creatine kinase antibodies. The muscle form of the kinase, on the one hand, is present throughout the entire T. marmorata electrocyte except in the nuclei. The brain form of the kinase, on the other hand, is predominantly located on the ventral, innervated face of the electrocyte, where it is closely associated with both surfaces of the postsynaptic membrane, and secondarily in the synaptic vesicles at the presynaptic terminal. Labeling of the noninnervated dorsal membrane is observed at the invaginated sac system. In the case of purified acetylcholine receptor-rich membranes, antibodies specific for chicken B-CK label only one face of the isolated vesicles. No immunoreaction is observed with anti-chicken M-CK antibodies. A discussion follows on the possible implications of these localizations of creatine kinase in connection with the function of the acetylcholine receptor at the postsynaptic membrane, the Na/K ATPase at the dorsal electrocyte membrane, and the ATP-dependent transmitter release at the nerve ending.
肌酸激酶（CK，EC 2.7.3.2）最近被鉴定为在多纹电鳐富含乙酰胆碱受体的膜中分子量为40,000 - 43,000的非受体外周v蛋白的中间等电点物种（pl 6.5 - 6.8）（巴兰特斯，F.J.，G.米埃克斯和T.瓦利曼，1983年，美国国家科学院院刊，80: 5440 - 5444）。在本研究中，通过免疫荧光以及对电细胞超薄冷冻切片或纯化的受体膜囊泡进行蛋白A - 金标记（使用亚基特异性抗鸡肌酸激酶抗体），在多纹电鳐电器官的细胞和亚细胞水平上证实了这一发现。一方面，激酶的肌肉形式存在于整个多纹电鳐电细胞中，但细胞核除外。另一方面，激酶的脑形式主要位于电细胞的腹侧、受神经支配的表面，在那里它与突触后膜的两个表面紧密相关，其次位于突触前终末的突触小泡中。在凹陷的囊泡系统处观察到非神经支配的背膜有标记。对于纯化的富含乙酰胆碱受体的膜，针对鸡B - CK的特异性抗体仅标记分离囊泡的一个面。用抗鸡M - CK抗体未观察到免疫反应。接下来将讨论肌酸激酶这些定位与突触后膜乙酰胆碱受体功能、背侧电细胞膜上的钠/钾ATP酶以及神经末梢处ATP依赖性递质释放之间可能的关联。
