Vanadate binding to the gastric hydrogen(1+)-transporting, potassium(1+)-stimulated ATPase and inhibition of the enzyme's catalytic and transport activities
Vanadate binding to the gastric hydrogen(1+)-transporting, potassium(1+)-stimulated ATPase and inhibition of the enzyme's catalytic and transport activities
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钒酸盐与胃氢 (1 ) 转运、钾 (1 ) 刺激的 ATP 酶结合并抑制该酶的催化和转运活性
DOI：
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
G. Sachs
中科院分区：
文献类型：
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作者：
L. Faller;E. Rabon;G. Sachs
研究了钒酸盐对胃镁依赖性、氢离子转运和钾刺激的腺苷三磷酸酶 (EC 3.6.1.3) (H,K-ATPase) 催化和转运活性的抑制作用。主要实验观察结果如下： (1)对5'-三磷酸腺苷(ATP)水解的抑制是双相的。化学计量为 1.5 nmol mg-1 的钒酸盐结合大约使生理温度下 K+ 刺激的 ATP 酶活性减半。剩余的活性通过结合额外的 1.5 nmol mg-1 钒酸盐和较低的表观离子来抑制，该钒酸盐以两种亲和力特异性地结合到胃囊泡。存在核苷酸时钒酸盐的结合与动力学上定义的高亲和力和低亲和力 ATP 位点的竞争相容。 (3) 钒酸盐单相抑制磷酸酶的形成和 K+ 刺激的对硝基苯基磷酸酶活性。最多形成 1.5 nmol mg-1 酸稳定磷酸酶。钒酸盐从抑制对硝基苯磷酸酯水解的位点解离的半衰期为 5 分钟 (4) 最多需要 3 nmol mg-1 钒酸盐来抑制质子转运。对数据最简单的解释是，钒酸盐通过在两个催化位点与 ATP 竞争性结合来抑制 H,K-ATP 酶。钒酸盐结合和磷酸酶形成的不同化学计量表明高亲和力和低亲和力位点的不同催化机制。
Vanadate inhibition of the catalytic and transport activities of the gastric magnesium-dependent, hydrogen ion transporting, and potassium-stimulated adenosinetriphosphatase (EC 3.6.1.3) (H,K-ATPase) has been studied. The principal experiment observations are the following: (1) Inhibition of adenosine 5'-triphosphate (ATP) hydrolysis is biphasic. Vanadate binding with a stoichiometry of 1.5 nmol mg-1 approximately halves K+-stimulated ATPase activity at physiological temperature. The remaining activity is inhibited by binding an additional 1.5 nmol mg-1 vanadate with lower apparent ions bind specifically to gastric vesicles with two affinities. Vanadate binding in the presence of nucleotide is compatible with competition for the kinetically defined high-affinity and low-affinity ATP sites. (3) Vanadate inhibits phosphoenzyme formation and the K+-stimulated p-nitrophenyl phosphatase activity of the enzyme monophasically. A maximum of 1.5 nmol mg-1 acid-stable phosphoenzyme is formed. The half-time for vanadate dissociation from the site that inhibits p-nitrophenyl phosphate hydrolysis is 5 min (4) At most, 3 nmol mg-1 vanadate is required to inhibit proton transport. The simplest interpretation of the data is that vanadate inhibits the H,K-ATPase by binding competitively with ATP at two catalytic sites. Different catalytic mechanisms at the high-affinity and low-affinity sites are suggested by the different stoichiometries found for vanadate binding and phosphoenzyme formation.
胃（H K ）-ATP酶功能和结构分子大小的目标分子量。
DOI：
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发表时间：
1981
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Saccomani,G;Sachs,G;Cuppoletti,J;Jung,CY
通讯作者：
Jung,CY