Measurement of serum PON-3 concentration: method evaluation, reference values, and influence of genotypes in a population-based study[S]

Abstract

Experimental studies showed that paraoxonase-3 (PON3) retards lipoprotein oxidation. Our objective was to describe a new assay to measure serum PON3 concentrations and report their reference values in a population-based study. The influence of PON3 promoter polymorphisms and their relationships with PON1 and lipid profile were also studied. We generated an anti-PON3 antibody by inoculating rabbits with a synthetic peptide specific to mature PON3. This antibody was used to develop an ELISA. The average regression line of standard plots (n = 8) was y = 0.9587 (0.3392) log10x + 1.9466 (0.0861) [r2= 0.924 (0.0131); P < 0.001]. There was no cross reaction with PON1. Detection limit was 0.24 mg/l. Imprecision was ≤13.2%. Reference interval (n = 356) was 1.00-2.47 mg/l. PON3 was observed in HDL particles containing apolipoprotein (apo)A-I and PON1, but not apoA-II or apoE. Serum PON3 concentrations showed a moderate influence (about 10% variation) by PON3 promoter polymorphisms. Our study describes for the first time a method to measure serum PON3 concentrations. This method offers new opportunities in the investigation of the properties and role of PON3 in cardiovascular disease, with possible implications in clinical practice.

Keywords

• analytical methods
• antioxidants
• atherosclerosis
• lipoproteins
• oxidative stress