钠钾ATP酶
The Na,K-ATPase.
作者信息
Skou J C, Esmann M
机构信息
Institute of Biophysics, University of Aarhus, Denmark.
出版信息
J Bioenerg Biomembr. 1992 Jun;24(3):249-61. doi: 10.1007/BF00768846.
The energy dependent exchange of cytoplasmic Na+ for extracellular K+ in mammalian cells is due to a membrane bound enzyme system, the Na,K-ATPase. The exchange sustains a gradient for Na+ into and for K+ out of the cell, and this is used as an energy source for creation of the membrane potential, for its de- and repolarisation, for regulation of cytoplasmic ionic composition and for transepithelial transport. The Na,K-ATPase consists of two membrane spanning polypeptides, an alpha-subunit of 112-kD and a beta-subunit, which is a glycoprotein of 35-kD. The catalytic properties are associated with the alpha-subunit, which has the binding domain for ATP and the cations. In the review, attention will be given to the biochemical characterization of the reaction mechanism underlying the coupling between hydrolysis of the substate ATP and transport of Na+ and K+.
哺乳动物细胞中依赖能量的胞质 Na⁺ 与细胞外 K⁺ 的交换是由一种膜结合酶系统——钠钾 ATP 酶介导的。这种交换维持了 Na⁺ 进入细胞和 K⁺ 流出细胞的梯度，并且该梯度被用作产生膜电位、使其去极化和复极化、调节胞质离子组成以及跨上皮运输的能量来源。钠钾 ATP 酶由两个跨膜多肽组成，一个 112-kD 的 α 亚基和一个 35-kD 的糖蛋白 β 亚基。催化特性与 α 亚基相关，α 亚基具有 ATP 和阳离子的结合结构域。在这篇综述中，将关注底物 ATP 水解与 Na⁺ 和 K⁺ 运输之间偶联反应机制的生化特性。
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