标题：Paraoxonase protection of LDL against peroxidation is independent of its esterase activity towards paraoxon and is unaffected by the Q→R genetic polymorphism
出版社：American Society for Biochemistry and Molecular Biology
摘要：High density lipoprotein (HDL)-associated paraoxonase (PON) seems to play a major role in the protection of low density lipoprotein (LDL) against peroxidation by HDL, and the partly purified enzyme exerts a dose-dependent protective effect. A common polymorphism of the human gene (192 Q→R) modulates paraoxonase activity but purified enzyme from either genotype is equally effective against LDL peroxidation. The inhibition of Cu2+-induced LDL peroxidation by HDL was monitored by lipid peroxide assay and change in LDL electrophoretic mobility. We show that HDL from type 2 diabetic patients with the QQ or RR genotype (n = 12 for each) reduce, to the same extent, both peroxide production (by 60.6 ± 20.0 and 63.9 ± 23.5%) and relative change in mobility (61.3 ± 21.8 and 61.4 ± 26.5%) despite a 6-fold difference in paraoxonase activity (47.4 ± 4.4 vs. 299.7 ± 23.7 U/l, P —Cao, H., A. Girard-Globa, F. Berthezene, and P. Moulin. Paraoxonase protection of LDL against peroxidation is independent of its esterase activity towards paraoxon and is unaffected by the Q→R genetic polymorphism. J. Lipid Res. 1999. 40: 133–139.
