A mechanistic study of the interaction of UVB radiations with human serum lipoproteins.
The tryptophan residues of HDL are important chromophores of the interstitial fluid feeding the epidermal cells. The UVB light readily photoionizes tryptophan residues as demonstrated by the increase in their photolysis yield in presence of N2O. Saturation of the HDL solution with a N2O/O2 mixture (80%:20%, v/v) decreases the peroxidation of HDL lipids, thereby implying that lipid peroxidation is at least partly induced by tryptophan photolysis. Addition of EDTA and desferrioxamine to HDL solutions loaded with either Cu2+ or Fe2+ ions suggests that Fe2+ could be the 'contaminating' trace metal ions that are required to explain the occurrence of lipid photoperoxidation induced by photons absorbed by tryptophan residues.
Salmon
S
S
Muséum National d'Histoire Naturelle, Laboratoire de Physico-chimie de l'Adaptation Biologique, INSERM U312, Paris, France.
Mazière
J C
JC
Santus
R
R
Morlière
P
P
D002614:Chelating Agents / Q000737:chemistry; D005561:Formates / Q000737:chemistry; D016166:Free Radical Scavengers; D006801:Humans; D015227:Lipid Peroxidation / Q000528:radiation effects; D008074:Lipoproteins / Q000097:blood / Q000737:chemistry / Q000528:radiation effects*; D008075:Lipoproteins, HDL / Q000528:radiation effects; D008670:Metals / Q000737:chemistry; D009609:Nitrous Oxide / Q000737:chemistry; D010084:Oxidation-Reduction / Q000528:radiation effects; D010777:Photochemistry; D010782:Photolysis; D013482:Superoxide Dismutase / Q000737:chemistry; D013858:Thiobarbiturates / Q000737:chemistry; D014364:Tryptophan / Q000737:chemistry; D014466:Ultraviolet Rays
D002614:Chelating Agents; D005561:Formates; D016166:Free Radical Scavengers; D008074:Lipoproteins; D008075:Lipoproteins, HDL; D008670:Metals; D013858:Thiobarbiturates; C030544:formic acid; D014364:Tryptophan; D013482:Superoxide Dismutase; D009609:Nitrous Oxide; C029684:thiobarbituric acid