Beta-carotene 9',10'-oxygenase (BCO2)

Beta-carotene 9',10'-oxygenase (BCO2) is a mitochondrial enzyme belonging to the carotenoid cleavage dioxygenase (CCD) family, primarily responsible for the asymmetric (eccentric) cleavage of carotenoids [UniProt: Q9BYV7]. While its cytoplasmic counterpart BCO1 performs the central cleavage of beta-carotene to produce vitamin A, BCO2 acts on a broader range of substrates, including non-provitamin A xanthophylls like lutein and zeaxanthin, converting them into apo-carotenoids [PubMed: 11435451]. This enzymatic activity is crucial for maintaining mitochondrial integrity, as the accumulation of intact carotenoids in the inner mitochondrial membrane can disrupt the electron transport chain and induce oxidative stress [PubMed: 21953444]. Clinically, BCO2 deficiency or genetic polymorphism is associated with hypercarotenemia, characterized by yellow skin pigmentation, and has been implicated in the pathogenesis of hepatic steatosis and age-related macular degeneration [PubMed: 24659303, PubMed: 22535975]. Although no small-molecule drugs currently target BCO2 in clinical practice, it is a focal point for developing precision nutrition strategies and understanding the metabolic flux of dietary antioxidants.

Other names

Beta-carotene 9',10'-dioxygenaseBCDO2Beta-carotene dioxygenase 2Carotene-9',10'-monooxygenase

Catalyzes the asymmetric (eccentric) oxidative cleavage of the 9',10' double bond in carotenoids, such as beta-carotene and xanthophylls, to produce apo-carotenoids.