Komarnitsky F B, Capozza G, Dukhovich V F, Chernyak B V, Papa S
A.N. Belozersky Laboratory of Molecular Biology and Bioorganic Chemistry, Moscow State University, USSR.
FEBS Lett. 1990 Oct 15;272(1-2):145-8. doi: 10.1016/0014-5793(90)80469-y.
Almost all ATPase molecules in submitochondrial particles, isolated from beef heart mitochondria in the presence of MgATP, are in an active complex with the natural protein inhibitor (IF1). In de-energized particles at high ionic strength a slow and irreversible ATPase activation is found to occur due to a dissociation of the enzyme-inhibitor complex. The pH-dependence of this process points out that deprotonation of IF1 molecule is an essential step in the dissociation of the complex. Zn2+ sharply accelerates ATPase activation, probably via binding with the deprotonated form of IF1. ATPase activation is completely prevented by MgATP, indicating the formation of a transient enzyme-inhibitor complex retaining ATPase activity.
在存在MgATP的情况下，从牛心线粒体中分离得到的亚线粒体颗粒中，几乎所有的ATP酶分子都与天然蛋白质抑制剂（IF1）形成活性复合物。在高离子强度的去能颗粒中，由于酶-抑制剂复合物的解离，会发生缓慢且不可逆的ATP酶激活。该过程对pH的依赖性表明，IF1分子的去质子化是复合物解离的关键步骤。Zn2+可能通过与IF1的去质子化形式结合，显著加速ATP酶的激活。MgATP可完全阻止ATP酶的激活，这表明形成了一种保留ATP酶活性的瞬时酶-抑制剂复合物。
