Biliverdin reductase B is a protein that in humans is encoded by the BLVRB gene.1HDO, 1HE2, 1HE3, 1HE4, 1HE5645233016ENSG00000090013ENSMUSG00000040466P30043Q923D2NM_000713NM_001290525NM_144923NP_000704NP_001277454NP_659172The BLVRB gene was localized to chromosome 19, the specific region being 19q13.13 to q13.2; this was done using fluorescence in situ hybridization.The final step in heme metabolism in mammals is catalyzed by the cytosolic biliverdin reductase enzymes A and B (EC 1.3.1.24). From a functional standpoint, it has been hypothesized that BLRVB is identical to flavin reductase (FR), an enzyme that catalyzes the NADPH-dependent reduction of FMN and Methylene Blue and, in the presence of redox couplers, the reduction of methaemoglobin.As BLVRB is a promiscuous enzyme catalysing the pyridine-nucleotide-dependent reduction of a variety of flavins, biliverdins, PQQ (pyrroloquinoline quinone), and ferric ion. Mechanistically it is a good model for BVR-A (biliverdin-IXalpha reductase), a potential pharmacological target for neonatal jaundice, and also a potential target for adjunct therapy to maintain protective levels of biliverdin-IXalpha during organ transplantation.BLVRB binds to human heme oxygenase-1 (hHO-1) in conjunction with cytochrome p450 reductase to catalyzes the NADPH-cytochrome P450 reductase-dependent oxidation of heme to biliverdin, CO, and free iron.This article incorporates text from the United States National Library of Medicine, which is in the public domain.