The enzymatic cleavage of beta-carotene: end of a controversy.
The central cleavage of dietary beta-carotene to retinal was found to be the predominant mechanism whereby retinoids were formed in vivo in rats; apo-carotenals, indicative of eccentric cleavage of beta-carotene, were only a minor component (<5% of retinoids). A gene from maize that codes for a plant carotenoid cleavage enzyme was used to isolate a homologous gene from Drosophila. This gene, when transfected into an E Coli strain capable of synthesizing and accumulating beta-carotene, caused the central cleavage of beta-carotene, forming exclusively retinoids. The enzyme that the gene codes for, beta-carotene-15,15'-dioxygenase, was purified and characterized.
Wolf
G
G
Department of Nutritional Sciences and Toxicology, University of California, Berkeley 94720-3104, USA.
D000818:Animals; D004330:Drosophila / Q000235:genetics; D029721:Drosophila Proteins; D006801:Humans; D010105:Oxygenases / Q000378:metabolism*; D014162:Transfection / Q000662:veterinary; D003313:Zea mays / Q000235:genetics; D019207:beta Carotene / Q000378:metabolism*; D050559:beta-Carotene 15,15'-Monooxygenase
D029721:Drosophila Proteins; C493360:ninaB protein, Drosophila; D019207:beta Carotene; D010105:Oxygenases; C493358:BCO1 protein, human; D050559:beta-Carotene 15,15'-Monooxygenase