Biliverdin reductase A（BLVRA) is a member of the gfo/idh/mocA family. BLVRA is an enzyme that converts biliverdin to bilirubin， converting a double-bond between the second and third pyrrole ring into a single-bond. BLVRA reduces the gamma-methene bridge of the open tetrapyrrole， biliverdin IX alpha， to bilirubin with the simultaneous oxidation of a NADH or NADPH cofactor（Bilirubin + NAD（P)+ = biliverdin + NAD（P)H ).
BLVRA is a regulator for induction of activating transcription factor-2 and heme oxygenase-1. Furthermore， BLVRA enhances the role of HO-1 in cytoprotection and provides cytoprotection independent of heme degradation. In addition， Bilirubin while acting as a cytoprotective antioxidant is itself oxidized to biliverdin and subsequently recycled by biliverdin reductase back to bilirubin.
