Nonspecific esterases of the formed elements: zymograms produced by pH 9.5 polyarcrylamide gel electrophoresis

The formed elements of human blood each contain multiple isoenzymes of nonspecific esterase that hydrolyze short chain alpha naphthyl esters. Zymograms that are characteristic of each type of formed element are obtained by subjecting purified preparations of each to polyacrylamide slab gel electrophoresis at pH 9.5 and subsequent staining of the gels for esterase activity. The most prominent isoenzyme detected is a species of low mobility that is reactive with either acetyl or butyryl esters and is highly sensitive to inhibition by 40 mM sodium fluoride. Also detected are several major acetyl esterases and a single butyryl esterase, all of which are relatively fluoride resistant. The intercellular distribution of isoenzymes varies from element-specific to pancellular. The prominent fluoride-sensitive acetyl, butyryl esterase, is the major isoenzyme of monocyte zymograms, which is consistent with the well known cytochemistry of monocytes. Lesser but significant amount (2%-3% of monocyte levels) of this isoenzyme were also detected in granulocyte zymograms. This system may prove useful in the study of differentiation of blood cells and in the classification of acute leukemias.