IS THERE A SPECIFIC LYSOPHOSPHOLIPASE IN HUMAN PANCREATIC-JUICE

The existence of a specific lysophospholipase in human pancreatic juic e was evaluated. The proteins were separated by a series of chromatogr aphic steps including Sephacryl S-200, cholate-Sepharose 4B, Sephadex G-100 and CM-Sephadex G-50. The enzyme activities against 1-palmitoyl lysolecithin (LL) as well as tributyrin (TB) and p-nitrophenyl butyrat e (PNPB) were determined in all the fractions of these purification pr ocedures. Enzyme activity against LL was always eluted in parallel wit h activities against TB and PNPB, and no unique activity against LL co uld be found. The specific activity against LL was 40-times lower than that against PNPB and 200-times lower than that against TB. It is con cluded that there is no unique lysophospholipase in human pancreatic j uice and that the hydrolysis of lysolecithin is most likely performed by carboxyl ester lipase.