The interaction between beta-carotene and lipoxygenase in plant and animal systems.
The effect of beta-carotene (BC) on the activity of lipoxygenase (LOX) from plant and animal sources has been examined. Soybean lipoxygenase L-2 activity towards linoleate was inhibited by BC by a maximum of 70% at pH 6.5, whereas L-1 activity was little affected at pH 9.0. Lineweaver-Burk plots indicated that BC inhibited LOX activity by mixed competitive/non-competitive mechanisms. Other hydrophobic compounds also inhibited LOX activity; oleic acid and retinol were competitive inhibitors whereas tocopherol acetate and 5,8,11,14-eicosatetraynoic acid (ETYA) were non-competitive inhibitors. Binding studies with L-2 LOX bound to Sepharose indicated BC-binding and inhibition with the immobilized LOX. Activity of LOX from animal sources was also inhibited by BC both towards linoleate and arachidonate.
Lomnitski
L
L
Department of Life Sciences, Bar Ilan University, Ramat Gan, Israel.
Bar-Natan
R
R
Sklan
D
D
Grossman
S
S
D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D001667:Binding, Competitive; D002338:Carotenoids / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D004800:Enzymes, Immobilized; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000378:metabolism; D008084:Lipoxygenase / Q000378:metabolism*; D016859:Lipoxygenase Inhibitors / Q000494:pharmacology*; D019301:Oleic Acid; D009829:Oleic Acids / Q000494:pharmacology; D010944:Plants / Q000201:enzymology; D051381:Rats; D014801:Vitamin A / Q000494:pharmacology; D019207:beta Carotene
D004800:Enzymes, Immobilized; D008041:Linoleic Acids; D016859:Lipoxygenase Inhibitors; D009829:Oleic Acids; D019207:beta Carotene; D014801:Vitamin A; D016718:Arachidonic Acid; D019301:Oleic Acid; D002338:Carotenoids; D019787:Linoleic Acid; D008084:Lipoxygenase