Isolation and characterization of a pancreatic elastase

1. An elastase-like enzyme in plasma of patients with acute pancreatitis was purified by DEAE-cellulose column chromatography and polyacrylamide-gel disc electrophoresis. 2. In this way 0.24 mg of purified enzyme with a specific activity of 3-94 succinyl-L-alanylL-alanyl-L-alanyl-p-nitroanilide units/mg of protein was obtained from 10 ml of plasma. 3. The purified material was homogeneous as ascertained by sodium dodecyl sulphatel polyacrylamide-gel disc electrophoresis and had an apparent molecular weight of 24000 as measured by gel filtration on Sephadex G100. 4. This enzyme hydrolysed denatured casein and Congo Red-elastin as well as succinylL-alanyl-L-alanyl-L-alanyl-p-nitroanilide. Its amidolytic activity was inhibited by soya bean trypsin inhibitor, but not by aprotinin. 5 . Although the enzyme was immunologically similar to elastase 2, its kinetic properties and substrate specificity were apparently different. 6. We propose that an elastase-like enzyme, probably different from elastase 1 or elastase 2, is liberated from the pancreas into blood during acute pancreatitis and becomes combined with $-macroglobulin.