ENZYME-IMMUNOASSAY FOR SPECIFIC ANALYSIS OF PANCREATIC STONE PROTEINS IN HUMAN PANCREATIC-JUICE

In order to study the concentration of pancreatic stone protein (PSP) in human pancreatic juice, we investigated the influence of the insoluble form ot PSP-S1 converted from PSP-S2-5 on PSP determination and the assay method for PSP-S1 precipitate after solubilizing PSP-S1. When bovine trypsin was added to pancreatic juice, PSP-S, was converted from PSP-S2-5 and precipitated about 45-85% after 1 h. The precipitated PSP-S1 was dissolved in 0.1 M sodium acetate buffer, pH 4.0, and the concentration was measured by the enzyme immunoassay, with similar reactivity to PSP-S1 and PSP-S2-5. The proposed method can offer accurate and specific analysis of the PSP level in pancreatic juice. The results of the fractionation of pancreatic juice and duodenal juice on Mono S cation-exchange chromatography suggested that the major component of PSP was PSP-S25 in pancreatic juice and PSP-S1 in duodenal juice.