Inhibition of 5-lipoxygenase by vitamin E.
Purified 5-lipoxygenase from potato tubers was inhibited strongly by vitamin E and its analogs. The inhibition by d-alpha-tocopherol was found to be irreversible and non-competitive with respect to arachidonic acid. An IC50 of 5 microM was calculated for d-alpha-tocopherol. The inhibition appears to be unrelated to its antioxidant function. Binding studies with 14C-labelled d-alpha-tocopherol revealed that there is a strong interaction between vitamin E and 5-lipoxygenase. Tryptic digestion and peptide mapping of 5-lipoxygenase-vitamin E complex indicate that vitamin E binds strongly to a single peptide. These studies suggest that cellular vitamin E levels may have profound influence on the formation of leukotrienes.
D000975:Antioxidants / Q000494:pharmacology; D002084:Butylated Hydroxytoluene / Q000494:pharmacology; D002396:Catechols / Q000494:pharmacology; D002850:Chromatography, Gel; D008084:Lipoxygenase / Q000378:metabolism; D016859:Lipoxygenase Inhibitors; D009637:Masoprocol; D011198:Solanum tuberosum / Q000201:enzymology; D014810:Vitamin E / Q000378:metabolism / Q000494:pharmacology*
D000975:Antioxidants; D002396:Catechols; D016859:Lipoxygenase Inhibitors; D014810:Vitamin E; D002084:Butylated Hydroxytoluene; D009637:Masoprocol; D008084:Lipoxygenase