Catalysis of the reaction: S-nitrosoglutathione + NADH + H+ = S-(hydroxysulfenamide)glutathione + NAD+.
Comment:
S-(hydroxysulfenamide)glutathione (GSNHOH) is an unstable intermediate. At high GSH levels, it is decomposed to glutathione disulfide (GSSG) and hydroxylamine. At low GSH levels, GSNHOH spontaneously converts to glutathione sulfinamid (GSONH2), which can be hydrolyzed to glutathione sulfinic acid (GSOOH) and ammonia. {xref="PMID:30795534"}