Identification of a non-specific carboxylesterase in human pancreas using vinyl 8-phenyloctanoate as a substrate

Human pancreatic tissue, pancreatic juice and sera of patients suffering from acute pancreatitis contain a vinyl 8-phenyloctanoate hydrolysing activity which was separated from true pancreatic lipase (EC 3.1.1.3). The enzyme, preliminary called "non-specific pancreatic carboxylesterase, was partially purified from human pancreatic tissue by DEAE-cellulose chromatography. Its molecular weight was found to be 54 000 by gel filtration on Sephadex G-100. The isoelectric point was estimated as 4.65 by isoelectric focusing. The results explain the poor correlation obtained when determinations of "serum lipase activity" using triolein and vinyl 8-phenyloctanoate as substrates are compared. However, since non-specific pancreatic carboxylesterase is liberated into the serum, determination of this new enzyme provides additional information in the diagnosis of pancreatic diseases.