[Isoelectric focusing of pure human pancreatic juice. 2. Identification of enzymes and proenzymes and characterization of glycoproteins].

Abstract

After isoelectric focusing of proteins of human pure pancreatic juice following digestive enzymes and zymogens were identified by substrate specific detection methods: in the anodic range trypsinogen 1, and acidic form of proelastase and procarboxypeptidase A; in the pH--range of 5.0-6.0 a trypsinogen--like protein and the secretory trypsin inhibitor; in the pH--range of 6.0-7.0 one form of each of procarboxypeptidase B, trypsinogen 2, lipase, chymotrypsinogen and two forms of alpha-amylase and in the cathodic range an activated form of procarboxypeptidase B, one form of prophospholipase A2 and an additional form of proelastase. In order to characterize glycoproteins the IEF separated pancreatic proteins were transferred onto nitrocellulose membranes. Using the periodic acid/Schiff's reagent (PAS) procedure five PAS-positive proteins (pl s 4.5; 6.0; 6.6; 6.9 and 7.3) were detected. Three Con A-binding proteins (pl s 6.0; 6.6 and 6.9) were identified by incubating the blot in Con A followed by peroxidase and o-phenylendiamin as a chromogenic peroxidase substrat.