Properties and classification of the soluble esterases of human liver

Abstract

Water-soluble enzymes of human liver were separated by zone electrophoresis in starch gel and compared with those of serum. Three separate zones of esterase activity in the liver extracts were found. An attempt was made to identify these enzymes by using several series of substrates and inhibitors in conjunction with various histochemical staining techniques. One enzyme, migrating at pH 7.2 toward the cathode, reacts like an acetylesterase. Another enzyme, migrating toward the anode at a rate approximating that of serum albumin, reacts like an aliesterase. A third region of activity contains a mixture of esterases and acid phosphatase. The organophosphorus anticholinesterases that were tested showed different patterns of inhibition of the liver esterases. Observations on alkaline phosphatase, sulphatase, glucosidase, galactosidase, and leucine aminopeptidase were recorded for comparison with the data on esterases.