... biliverdin. Biliverdin-IXa reductase(BVR-A) is most active with its physiological substrate biliverdin-IXa, butcan also reduce the three other biliverdin isomers IXb,IXd and IXc. Bili-verdin-IXb ... 18-ethylbiliverdin-IXa; BVR-A, biliverdin-IXa reductase; BVR-B, biliverdin-IXb reductase; DDQ, 2,3-dichloro-5,6-dicyanobenzoquinone;hBVR-A, human biliverdin-IXa reductase; hBVR-B, human biliverdin-IXb ... enzymes is that BVR-B catalyses the reductionof biliverdin-IXb, biliverdin-IXd and biliverdin-IXc,but not biliverdin-IXa [2,10]. BVR-A prefers biliverdin-IXa as substrate, but can reduce all three...