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

• Published in: Biochemical pharmacology 1997-02, Vol.53 (4), p.581-585
• Main Authors: Demaster, Eugene G., Quasi, Barry J., Mitchell, Robert A.
• Format: Article
• Language: English
• Subjects: Aerobiosis; Chemistry; Elements and non-metal compounds (oxides, hydroxides, hydrides, sulfides, carbides, ...); Exact sciences and technology; glutathione; Glutathione - analogs & derivatives; Glutathione - metabolism; Hydrogen-Ion Concentration; Inorganic chemistry and origins of life; nitric oxide; Nitric Oxide - metabolism; nitrosation; Nitroso Compounds - metabolism; Oxidation-Reduction; Phosphates - pharmacology; Preparations and properties; S-Nitrosoglutathione
• ISSN: 0006-2952; 1873-2968
• DOI: 10.1016/S0006-2952(96)00825-8

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 Snitrosation reaction from 20 to 40%, whereas SO −2 4, H 3BO 3, SCN −, NO 3, Cl −, and acetate inhibited this reaction ⩽15%. A mechanism of inhibition is presented that involves the catalytic hydrolysis of N 2O 3 by the bifunctional anions; however, using [ 18O]phosphate as inhibitor, only 10% of the theoretically produced N 2O 3 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.