title: UVB-induced photoperoxidation of lipids of human low and high density lipoproteins. A possible role of tryptophan residues.
abstract: Ultraviolet radiation of the UVB region readily destroy tryptophan (Trp) residues of low (LDL) and high (HDL) density lipoproteins. The photooxidation of tryptophan residues is accompanied by the peroxidation of low and high density lipoproteins unsaturated fatty acids, as measured by the thiobarbituric acid assay. Moreover, low and high density lipoproteins are natural carriers of vitamin E and carotenoids. These two antioxidants are also rapidly bleached by UVB. The UVA radiation promotes neither tryptophan residue destruction nor lipid photoperoxidation. The redox cycling Cu2+ ions considerably increase lipid photoperoxidation. The synergistic action of photo and auto (Cu2(+)-induced) peroxidation induces marked post-irradiation modifications of apolipoproteins as illustrated by the degradation of most tryptophan residues after overnight incubation in the dark of pre-irradiated samples.
authors: Muséum National d'Histoire Naturelle, INSERM U312, Paris, France.
authors: S
authors: S
authors: Salmon
authors: J C
authors: JC
authors: Maziere
authors: R
authors: R
authors: Santus
authors: P
authors: P
authors: Morliere
authors: N
authors: N
authors: Bouchemal
mesh_terms: D003300:Copper / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D006801:Humans; D015227:Lipid Peroxidation; D008075:Lipoproteins, HDL / Q000097:blood* / Q000528:radiation effects; D008077:Lipoproteins, LDL / Q000097:blood* / Q000528:radiation effects; D014364:Tryptophan; D014466:Ultraviolet Rays
chemical_list: D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D003300:Copper; D014364:Tryptophan; D004492:Edetic Acid