Catalytic properties and distribution profiles of paraoxonase and cholinesterase phenotypes in human sera

Abstract

Paraoxonase activities (322 healthy subjects) measured in the absence of ethylenediaminetetraacetic acid (EDTA) had a polymodal distribution profile with 60% of the subjects in the low activity mode; the activity measured in the presence of EDTA had a unimodal skewed distribution. Cholinesterase (ChE) activities (365 healthy subjects) had a unimodal, slightly skewed distribution. Patients with dementia (74) and patients with hyperlipidaemia (159) had different median paraoxonase and ChE activities than healthy subjects and all activity profiles had a higher skewness. The ChE variants usual (UU), fluoride resistant (FS) and atypical (AA) had the same affinity for the studied charged and uncharged ligands. The variants differed in rates of inhibition by the charged organophosphates and carbamates.