Figure 2.

Mechanism of GSH-mediated denitrosylation of PSNOs. S-nitrosylated proteins can be denitrosylated by reduced glutathione (GSH), forming protein with reduced thiol(s) and GSNO, which is metabolized by ubiquitously expressed GSH into a stable disulfide form (GSSG) at the expense of HNO. GSSG (oxidized GSH) can be further reduced back to GSH by NADPH-dependent GR. Alternatively, GSNO can also be irreversibly metabolized by GSNOR to a complex N-hydroxysulphenamide (GSNHOH) form, utilizing reducing equivalents from NADH [3,42].