The role of (alpha beta) protomer interaction in determining functional characteristics of red cell Na,K-ATPase.
The role of (alpha beta) protomer interaction in determining functional characteristics of red cell Na,K-ATPase.
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（αβ）原体相互作用在确定红细胞 Na,K-ATP 酶功能特征中的作用。
DOI：
10.1016/0005-2736(94)90349-2
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Sachs,JR
中科院分区：
文献类型：
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作者：
Sachs,JR
我们通过检查它们对两种抑制剂的反应，即共价结合的 FITC 和 H2DIDS，以及缓慢从红细胞泵脱结合的哇巴因，研究了双原体内 (αβ) 原体的相互作用是否导致红细胞 Na,K-ATP 酶的一些异常特征。我们检查的现象是：(1) 将 Na,K-ATP 酶活性与 ATP 浓度相关的双相曲线，以及 (2) 保护 Na 泵免受外部 Na 的钒酸盐抑制。如果二原体内的（αβ）原体的相互作用是造成这些现象的原因，那么（αβ）原体的随机失活应该导致高比例的（αβ）原体与受抑制的原体作为伙伴，因此应该显着改变亚基相互作用的结果。对于每种抑制剂，ATP酶活性的60-70%抑制不会改变残余活性的功能特征。我们得出的结论是，功能性（αβ）原体的相互作用并不能解释我们所研究的现象。这与我们之前的观察结果一致，即红细胞膜的 Na,K 泵以单体 (αβ) 原聚体的形式存在（Martin, D.W. 和 Sachs, V.R. (1992) J. Biol. Chem. 267, 23922–23929）。
We have examined the possibility that interaction of (αβ) protomers within a diprotomer is responsible for some anomalous characteristics of red cell Na,K-ATPase by examining their response to two inhibitors, FITC and H2DIDS, which bind covalently, and to ouabain, which debinds slowly from red cell pumps. The phenomena we examined were: (1) the biphasic curve relating Na,K-ATPase activity to ATP concentration, and (2) protection of Na pumps against vanadate inhibition by external Na. If interaction of (αβ) protomers within a diprotomer were responsible for these phenomena, random inactivation of (αβ) protomers should have resulted in a high proportion of (αβ) protomers with an inhibited protomer as a partner, and therefore should have significantly altered the consequences of subunit interaction. With each inhibitor, 60–70% inhibition of ATPase activity did not alter the functional characteristics of the residual activity. We conclude that interaction of functional (αβ) protomers does not explain the phenomena which we investigated. This is consistent with our previous observation that Na,K pumps of red cell membranes exist as monomeric (αβ) protomers (Martin, D.W. and Sachs, V.R. (1992) J. Biol. Chem. 267, 23922–23929).