Inhibition of S-nitrosation of reduced glutathione in aerobic solutions of nitric oxide by phosphate and other inorganic anions.
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.
DeMaster
E G
EG
Medical Research Laboratories, VA Medical Center, Minneapolis, MN 55417, USA.
Quast
B J
BJ
Mitchell
R A
RA
D000332:Aerobiosis; D005978:Glutathione / Q000031:analogs & derivatives* / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D009569:Nitric Oxide / Q000378:metabolism*; D009603:Nitroso Compounds / Q000378:metabolism*; D010084:Oxidation-Reduction; D010710:Phosphates / Q000494:pharmacology*; D026422:S-Nitrosoglutathione
D009603:Nitroso Compounds; D010710:Phosphates; D009569:Nitric Oxide; D026422:S-Nitrosoglutathione; D005978:Glutathione