MULTIPLE FORMS OF HUMAN LIVER ESTERASES

Abstract

Zone electrophoresis in starch gel of the water-soluble human liver esterases resulted in the separation of three zones of activity, each composed of several bands. The relative sizes of the enzymes in each zone were studied by utilizing the relative retardation of the electrophoretic migration induced by changes in the concentration of starch. On the basis of graphic analysis, four esterase bands comprising the zone migrating towards the cathode were found to be similar in molecular size or shape. A similar observation was made for seven bands comprising a zone migrating towards the anode. Taken with the substrate specificities and sensitivities toward various inhibitors, these observations strengthen the hypothesis that at least two of the hepatic esterases, an acetylesterase and an aliesterase, exist as multiple forms, differing primarily in net electrical charge.