FunctionHydrolyzes the toxic metabolites of a variety of organophosphorus insecticides. Capable of hydrolyzing a broad spectrum of organophosphate substrates and lactones, and a number of aromatic carboxylic acid esters. Mediates an enzymatic protection of low density lipoproteins against oxidative modification and the consequent series of events leading to atheroma formation.
Tissue specificityPlasma, associated with HDL (at protein level). Expressed in liver, but not in heart, brain, placenta, lung, skeletal muscle, kidney or pancreas.
Involvement in diseaseGenetic variation in PON1 is associated with susceptibility to microvascular complications of diabetes type 5 (MVCD5) [MIM:612633]. These are pathological conditions that develop in numerous tissues and organs as a consequence of diabetes mellitus. They include diabetic retinopathy, diabetic nephropathy leading to end-stage renal disease, and diabetic neuropathy. Diabetic retinopathy remains the major cause of new-onset blindness among diabetic adults. It is characterized by vascular permeability and increased tissue ischemia and angiogenesis. Note=Homozygosity for the Leu-54 allele is strongly associated with the development of retinal disease in diabetic patients.
Sequence similaritiesBelongs to the paraoxonase family.
Post-translational modificationsGlycosylated. The signal sequence is not cleaved. Present in two forms, form B contains a disulfide bond, form A does not.