Oxidation of low-density lipoprotein by Cu2+ and lipoxygenase: an electron spin resonance study.
The aim of this work was to obtain spectroscopic evidence for free radicals formed during copper ion- and lipoxygenase-catalyzed oxidation of the low-density lipoprotein. During the initial oxidation phase, a free-radical metabolite derived from the endogenous alpha-tocopherol present in the low-density lipoprotein was detected by the electron spin resonance technique. The divalent copper ions were bound to the residual EDTA present in the low-density lipoprotein and to the protein. Production of the alpha-tocopherol radical was suppressed in the presence of spin traps. Evidence for the low-density lipoprotein-lipid derived radicals was obtained by ESR-spin trapping methods. Implications of these findings in the oxidative modification of the low-density lipoprotein are discussed.
Kalyanaraman
B
B
Department of Radiology, Medical College of Wisconsin, Milwaukee 53226.
Antholine
W E
WE
Parthasarathy
S
S
D003300:Copper / Q000378:metabolism* / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals; D006801:Humans; D007700:Kinetics; D015227:Lipid Peroxidation; D008077:Lipoproteins, LDL / Q000097:blood*; D008084:Lipoxygenase / Q000378:metabolism*; D008954:Models, Biological; D011485:Protein Binding
D005609:Free Radicals; D008077:Lipoproteins, LDL; D003300:Copper; D008084:Lipoxygenase