Über Proteaseinhibitoren, I. Isolierung und Charakterisierung des Trypsininhibitors aus Pankreasgewebe und Pankreassekret vom Hund

Abstract

A trypsin inhibitor was purified more than 1,000-fold from the tissues and secretion of dog pancreas. The decisive purification step consists of gel filtration of the trypsin-inhibitor complex, its final cleavage in acid solution by means of gel filtration again. The inhibitor obtained in this way has a specific activity of 3.0 inhibitor tnilli-units (ImU) per [mu]g of protein and a molecular weight of about 7,200. By electrophoresis on cellulose acetate sheets, it is separated into 3 basic polypeptides, of which at least 2 possess inhibitor activity. Except for trypsin, the inhibitor inhibits none of the known proteinases and peptidases. It is destroyed by pepsin, but not by trypsin and chymotrypsin under the conditions of investigation. The inhibition of trypsin was tested with the aid of the very exact determination of trypsin activity with the substrate N[alpha]-benzoyl-DL-arginine-p-nitroanilide.