Functional studies with the octameric and dimeric form of mitochondrial creatine kinase. Differential pH-dependent association of the two oligomeric forms with the inner mitochondrial membrane.
Functional studies with the octameric and dimeric form of mitochondrial creatine kinase. Differential pH-dependent association of the two oligomeric forms with the inner mitochondrial membrane.
复制标题
线粒体肌酸激酶八聚体和二聚体形式的功能研究。
DOI：
10.1016/s0021-9258(19)38835-0
复制
发表时间：
1990
期刊：
影响因子：
--
通讯作者：
T. Wallimann
中科院分区：
文献类型：
--
作者：
J. Schlegel;M. Wyss;H. Eppenberger;T. Wallimann
从新鲜分离的鸡心肌的完整线粒体中磷酸盐提取线粒体肌酸激酶（Mi-CK，EC 2.7.3.2），在低渗介质中短暂溶胀后，产生超过90%的八聚体和仅少量的二聚体Mi-CK，这是通过在提取酶后立即对上清液进行快速蛋白质液相色谱-凝胶渗透分析来判断的。在提取缓冲液中，八聚体Mi-CK显示出解离成稳定二聚体的趋势，尽管速率较慢，半衰期约为3-5天。用纯化的Mi-CK八聚体或二聚体或其确定的混合物在相同条件下与Mi-CK耗尽的有丝分裂体孵育的实验显示，Mi-CK的两种寡聚体形式都可以重新结合到有丝分裂体。然而，该协会的Mi-CK是强烈的pH值依赖性，此外，八聚体和二聚体的Mi-CK表现出不同的pH值依赖性的重新绑定。因此，在某些pH条件下，可以重新结合两种寡聚体形式或选择性地仅结合八聚体。此外，有证据表明，Mi-CK二聚体部分形成八聚体后重新绑定到内膜。两种寡聚Mi-CK形式与线粒体内膜的差异缔合以及八聚体和二聚体Mi-CK之间的动态平衡（Schlegel，J.，Shakesbriggen，B.，Wegmann，G.，Wessel，M.，Eppenberger，HM，和Wallimann，T.（1988）生物化学杂志，263，16942-16953）表明两种寡聚体形式都是生理学相关的。八聚体与二聚体比率的变化通常可以影响Mi-CK的缔合行为，从而调节线粒体能量通量，如在磷酰基肌酸回路模型中所讨论的（Wallimann，T.，Schnyder，T.，Schlegel，J.，Wessel，M.，Wegmann，G.，Rossi，A. M.，Hemmer，W.，Eppenberger，H.M.，Quest，A.F.G.（1989）Prog.临床生物学研究315，159-176。
Phosphate extraction of mitochondrial creatine kinase (Mi-CK, EC 2.7.3.2) from freshly isolated intact mitochondria of chicken cardiac muscle, after short swelling in hypotonic medium, yielded more than 90% of octameric and only small amounts of dimeric Mi-CK as judged by fast protein liquid chromatography-gel permeation analysis of the supernatants immediately after extraction of the enzyme. In extraction buffer, octameric Mi-CK displayed a tendency to dissociate, albeit at a slow rate with a half-life of approximately 3-5 days, into stable dimers. Experiments with purified Mi-CK octamers or dimers, or defined mixtures thereof, incubated under identical conditions with Mi-CK-depleted mitoplasts revealed that both oligomeric forms of Mi-CK can rebind to mitoplasts. However, the association of Mi-CK was strongly pH-dependent and, in addition, octameric and dimeric Mi-CK showed different pH dependences of rebinding. Therefore, it was possible under certain pH conditions to rebind either both oligomeric forms or selectively the octamers only. Furthermore, evidence is presented that Mi-CK dimers partially form octamers upon rebinding to the inner membrane. The differential association of the two oligomeric Mi-CK forms with the inner mitochondrial membrane together with the dynamic equilibrium between octameric and dimeric Mi-CK (Schlegel, J., Zurbriggen, B., Wegmann, G., Wyss, M., Eppenberger, H.M., and Wallimann, T. (1988) J. Biol. Chem., 263, 16942-16953) suggest that both oligomeric forms are physiologically relevant. A change in the octamer to dimer ratio may influence the association behavior of Mi-CK in general and thus modulate mitochondrial energy flux as discussed in the phosphoryl creatine circuit model (Wallimann, T., Schnyder, T., Schlegel, J., Wyss, M., Wegmann, G., Rossi, A.-M., Hemmer, W., Eppenberger, H.M., and Quest, A.F.G. (1989) Prog. Clin. Biol. Res. 315, 159-176.