磷酸盐及其他无机阴离子对一氧化氮有氧溶液中还原型谷胱甘肽亚硝化作用的抑制。

Inhibition of S-nitrosation of reduced glutathione in aerobic solutions of nitric oxide by phosphate and other inorganic anions.

作者信息

DeMaster E G, Quast B J, Mitchell R A

机构信息

Medical Research Laboratories, VA Medical Center, Minneapolis, MN 55417, USA.

出版信息

Biochem Pharmacol. 1997 Feb 21;53(4):581-5. doi: 10.1016/s0006-2952(96)00825-8.

DOI:10.1016/s0006-2952(96)00825-8

PMID:9105410

Abstract

Reduced glutathione is nitrosated in aerobic solutions of nitric oxide under physiological conditions; however, the extent of S-nitrosation was found to be dependent on the inorganic anions present. Of nine anions tested, the bifunctional anions, arsenate, phosphate, and pyrophosphate (40 mM), inhibited the S-nitrosation reaction from 20 to 40%, whereas SO4(2-), H3BO3, SCN-, NO3-, Cl-, and acetate inhibited this reaction < or = 15%. A mechanism of inhibition is presented that involves the catalytic hydrolysis of N2O3 by the bifunctional anions; however, using [18O]phosphate as inhibitor, only 10% of the theoretically produced N2O3 was found to be hydrolyzed to nitrite via this mechanism as calculated from the loss of 18O from phosphate. We conclude that this mechanism accounts for only a minor part of the increased inhibition of S-nitrosation by these bifunctional anions.

摘要

在生理条件下，还原型谷胱甘肽在一氧化氮的有氧溶液中会发生亚硝化反应；然而，发现S-亚硝化的程度取决于存在的无机阴离子。在测试的九种阴离子中，双功能阴离子、砷酸盐、磷酸盐和焦磷酸盐（40 mM）可使S-亚硝化反应的抑制率达到20%至40%，而硫酸根离子、硼酸、硫氰酸根离子、硝酸根离子、氯离子和醋酸根离子对该反应的抑制率≤15%。本文提出了一种抑制机制，该机制涉及双功能阴离子对三氧化二氮的催化水解；然而，使用[18O]磷酸盐作为抑制剂时，根据磷酸盐中18O的损失计算，通过该机制理论上生成的三氧化二氮中只有10%水解为亚硝酸盐。我们得出结论，该机制仅占这些双功能阴离子对S-亚硝化抑制作用增强的一小部分。