Enhanced susceptibility of cholesteryl sulfate-enriched low density lipoproteins to copper-mediated oxidation.

Cholesteryl sulfate (CS) is a minor component of cell membranes, also present in lipoproteins, and its exact function is unknown. Since oxidation of low density lipoproteins (LDL) is thought to be an important determinant of atherogenesis, we investigated the influence of CS enrichment on copper-mediated oxidation of LDL. CS was found to act as a pro-oxidant, as measured by lipid oxidation parameters. The results also suggest that these effects were dependent on the sulfate group since pure cholesterol or cholesteryl acetate did not promote Cu(2+)-mediated oxidation. Our findings imply that CS may affect the oxidizability and hence the potential atherogenicity of LDL.