Regulation of Na+, K+-ATPase by the endogenous sodium transport inhibitor from hypothalamus.
Regulation of Na+, K+-ATPase by the endogenous sodium transport inhibitor from hypothalamus.
复制标题
下丘脑内源性钠转运抑制剂对 Na , K -ATP 酶的调节。
DOI：
10.1161/01.hyp.10.5_pt_2.i61
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
HaupertJr,GT
中科院分区：
文献类型：
--
作者：
HaupertJr,GT
我们的特点的影响，小，nonpeptidic分子分离牛下丘脑哺乳动物Na+，K+-腺苷三磷酸酶（ATP酶）。这种下丘脑因子已被证明具有高亲和力可逆地抑制纯化的狗肾酶的ATP酶活性。本文就其抑制机制作一综述。下丘脑因子仅从细胞外表面抑制Na+，K+-ATP酶。它防止Na+，K+-ATP酶活性位点天冬氨酸残基的镁和无机磷酸盐磷酸化，并使酶稳定在E2构象，防止钠诱导的从E2到E1的转变。下丘脑因子在培养的肾小管上皮细胞中的结合和解离反应显示出与分离膜不同的时间范围，并且与生理相关性一致。讨论了Na+，K+-ATP酶生理调节的可能机制，包括完整肾小管细胞中的结合和快速解离循环。
We characterized the effect of a small, nonpeptidic molecule isolated from bovine hypothalamus on mammalian Na+, K+-adenosine triphosphatase (ATPase). This hypothalamic factor has been shown to inhibit ATPase activity of purified dog kidney enzyme reversibly with high affinity. This report reviews the mechanism of inhibition. Hypothalamic factor inhibits Na+, K+-ATPase only from the extracellular surface. It prevents the phosphorylation from magnesium and inorganic phosphate of the active site aspartate residue of Na+, K+-ATPase and stabilizes the enzyme in an E2 conformation, preventing a sodium-induced shift from E2 to E1. Binding and dissociation reactions of hypothalamic factor in cultured renal tubular epithelial cells show a time frame different from that in isolated membranes and consistent with physiological relevance. A possible mechanism for the physiological regulation of Na+, K+-ATPase, including a cycle of binding and rapid dissociation in intact renal tubular cells, is discussed.