Fig. 2

Relationship between PON1 epigenetics and substrate-specific enzymatic activity. Graphs indicating the association of average promoter methylation and -108 methylation on serum lactonase (a) and arylesterase (b) in a population of 45 patients with a wide range of (hepato)metabolic derangements. Methylation is represented as M-values; positive M-values mean that more molecules are methylated than unmethylated (> 50% methylation) while negative M-values mean the opposite (< 50% methylation). Activity levels are expressed as units per millilitre of serum, in which 1 unit equals 1 mmol of 5-thiobutyl butyrolactone (lactone-hydrolysing activity) or phenyl acetate (arylester-hydrolysing activity) hydrolysed/min. The significance level (p) and FDR threshold (q) were set at 0.05