Beta-carotene oxygenase 2 (BCO2)

Beta-carotene oxygenase 2 (BCO2) is a mitochondrial enzyme that catalyzes the oxidative cleavage of carotenoids (including beta-carotene, lycopene, and xanthophylls such as zeaxanthin and lutein) at the 9,10 and 9',10' bonds, generating apocarotenoids[2][1]. BCO2, part of the carotenoid cleavage oxygenase (CCO) superfamily, contains a characteristic RPE65 domain and is widely expressed across tissues in vertebrates and invertebrates, often with highest expression in metabolically active tissues[1][3]. The enzyme regulates carotenoid homeostasis, modulating body/tissue pigmentation and mediating protection against oxidative stress by preventing excessive carotenoid deposition[1][3]. Mutations or reduced expression of BCO2 can result in carotenoid accumulation and have been linked to pigmentation variations in several animals[1][3]. There are currently no approved drugs that directly target BCO2, but SNPs in BCO2 serve as biomarkers for carotenoid status and associated phenotypes[3][2]. The enzyme plays a biologically important role in vitamin A biosynthesis from dietary carotenoids[2].

Other names

Carotenoid-cleaving dioxygenase, mitochondrialBeta-carotene 9',10'-oxygenaseBeta,beta-carotene 9',10'-oxygenaseBeta-carotene dioxygenase 2Carotenoid-9',10'-cleaving dioxygenaseBCO2BCDO2B-DIOX-IIB-diox-IIFLJ34464

Not established for drugs, but enzyme activity involves asymmetric oxidative cleavage of carotenoids at the 9,10 and 9',10' carbon-carbon double bonds using Fe²⁺ as a cofactor