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美国卫生研究院文献>Biochemical Journal
>Organization of thiol groups of electric-eel electric-organ sodium-plus-potassium ion-stimulated adenosine triphosphatase studied with bifunctional reagents.
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Organization of thiol groups of electric-eel electric-organ sodium-plus-potassium ion-stimulated adenosine triphosphatase studied with bifunctional reagents.
The reactions of three bifunctional thiol-blocking reagents of differing cross-linking spans and two monofunctional thiol-blocking reagents with the Na+ + K+-stimulated ATPase of the electric-eel electric organ were examined. 1,5-Difluoro-2,4-dinitrobenzene with a cross-linking span of 0.3--0.5 nm (3--5 A) and high solubility in non-polar solvent was the most efficient inhibitor of enzyme activity; thus essential thiol groups exist in a non-polar environment and are approx. 0.3--0.5 nm (3--5 A) from their nearest thiol-group neighbours. Ligands promoting phosphorylation of the Na+ + K+-stimulated ATPase decreased the number of thiol groups bridged by 1,5-difluoro-2,4-dinitrobenzene and by 4,4'-difluoro-3,3'-dinitrodiphenyl sulphone [0.7--1.0 nm (7--10 A) span]. Phosphorylation is associated with a conformational change in the enzyme.
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机译:考察了三种交联跨度不同的双功能硫醇阻断剂和两种单官能硫醇阻断剂与电器官中Na + + K +刺激的ATPase的反应。 1,5-二氟-2,4-二硝基苯的交联跨度为0.3--0.5 nm(3--5 A),在非极性溶剂中的溶解度高,是最有效的酶活性抑制剂;因此,必需的硫醇基团存在于非极性环境中,大约为。离他们最近的硫醇基团邻居0.3--0.5 nm(3--5 A)。促进Na + + K +刺激的ATPase磷酸化的配体减少了被1,5-二氟-2,4-二硝基苯和4,4'-二氟-3,3'-二硝基二苯砜桥接的巯基的数量[0.7-- 1.0 nm(7--10 A)跨度]。磷酸化与酶的构象变化有关。
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