PURIFICATION AND SUBSTRATE AND INHIBITOR SPECIFICITIES OF CARBOXYLESTERASES OF PEA (PISUM SATIVUM L.)

1. 1. Carboxylesterases (carboxylic ester hydrolase, EC 3.1.1.1) active toward phenyl propionate were purified from an aqueous extract of the pea (Pisum sativum L.) by precipitation of inactive material with protamine sulfate and chromatography on Sephadex G-100 and DEAE cellulose. Three active fractions were obtained. 2. 2. Inhibitor specificities determined with DFP, diethyl p-nitrophenyl thiophosphate and p-chloromercuribenzoate, and substrate specificity toward nine substrates indicated that two of these fractions were isozymes. The third fraction, which had differences in inhibitor and substrate specificities, showed one major esterase band on polyacrylamide-gel electrophoresis. © 1968.