CATALYTIC PROPERTIES AND DISTRIBUTION PROFILES OF PARAOXONASE AND CHOLINESTERASE PHENOTYPES IN HUMAN SERA

Paraoxonase activities (322 healthy subjects) measured in the absence of ethylenediaminetetraactic acid (EDTA) had a polymodal distribution profile with 60% of the subjects in the low activity mode; the activit y 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 patien ts with hyperlipidaemia (159) had different median paraoxonase and ChE activities than healthy subjects and all activity profiles had a high er skewness. The ChE variants usual (UU), fluoride resistant (FS) and atypical (AA) had the same affinity for the studied charged and unchar ged ligands. The variants differed in rates of inhibition by the charg ed organophosphates and carbamates.