STUDIES ON AROMATIC ESTERASE AND CHOLINESTERASE OF HUMAN SERUM

Abstract

Human serum proteins were separated by electrophoresis on filter paper. Cholinesterase could not be readily eluted from the paper but was demonstrated to be between α2- and β-globulins by a staining method. Aromatic esterase migrated in close relation to albumin and could be eluted by M/15 phosphate buffer of pH 7.4. The esterase activity was demonstrated in the eluates by ultraviolet spectrophotometry, using phenylacetate as a substrate. Versene caused a strong inhibition of aromatic esterase activity in vitro. The activity could be restored by different cations of which Ca++, Cu++, and Mn++were most potent. In 74 persons who were considered as normal controls in regard to the esterases, there was no correlation between cholinesterase and aromatic esterase activity. However, in 25 individuals suffering from cancer and/or liver dysfunction, a significant correlation between the two enzyme activities appeared.