Action of Water-insoluble Trypsin Derivatives on Pepsinogen

SUMMARY The action, on pepsinogen, of water-insoluble trypsin prepared by polymerization of the enzyme with maleic acid and ethylene was compared with that of trypsin. It was established that, whereas trypsin hydrolyzes 15 peptide bonds in pepsinogen, the maximum number of bonds cleaved by water-insoluble trypsin never exceeds 10. This result is independent of the ratio of carrier to enzyme. Furthermore, the same difference is observed if reduced carboxymethylated pepsinogen is used as substrate. If the chromatographically separated fractions of the two types of digests are compared by high voltage electrophoresis and chromatography, different peptide maps are obtained. Thus it can be concluded that water-insoluble trypsin possesses a more selective specificity toward high molecular