Abstract
Esterases from the blood of young adult male C-57 brown mice were separated by starch gel electrophoresis. Enzymatic hydrolysis of the substrates α-naphthyl acetate, naphthyl-AS acetate, α-naphthyl butyrate and acetylthiocholine was studied. Three different esterases were found in erythrocytes. One band hydrolyzed a-naphthyl butyrate but was only slightly active with acetate esters. The fastest migrating bands hydrolyzed acetate faster than butyrate esters, but would hydrolyze both substrates. A third esterase represented in the zymogram by a pair of bands (called "acetate" bands) would hydrolyze only acetate esters. When heparin, or plasma containing heparin, was inserted in a gel so as to overlap an erythrocyte sample, only the acetate bands were altered. When hepanin was inserted cathodal to an erythrocyte sample, the acetate bands are selectively affected by the heparin in such a way as to cause the acetate band to migrate more rapidly toward the anode; other esterase bands were not similarly affected. Acetate bands were not inhibited by physostygmine (1 mM) but their activities diminished with increased concentrations of buffer.