| Abstrakt: |
Interaction of rabbit small intestine mucosa beta-carotene 15,15'-dioxygenase with lycopene, 15,15'-dehydro-beta-carotene, lutein and astaxanthine is unaccompanied by the formation of products of enzymatic cleavage of the central double bond of these carotenoid molecules. Apo-carotenoids of lutein and lycopene are formed by nonenzymatic oxidation. Lycopene and 15,15'-dehydro-beta-carotene competitively inhibit the enzymatic oxidation of beta-carotene. Inhibition of the enzyme conversion by lutein and astaxanthin is less strong, being of a competitive-noncompetitive type. Enzymatic formation of retinal from beta-carotene depends on the accessibility of substrate molecules. |
