title: Purification and partial characterization of human pancreatic elastase.
abstract: 1) An elastolytic enzyme has been isolated from human pancreatic juice. The concentration of the enzyme was about 0.6 mg/ml corresponding to about 10% of the protein concentration of the juice. 2) The purification procedure included chromatography on Sephadex G-25 followed by ion-exchange chromatography on SP-Sephadex C-50 at pH 6.0, affinity chromatography on Trasylol-Sepharose 4-B and a final ion-exchange chromatography on SP-Sephadex at pH 7.6. The yield was about 50%. 3) The elastase isolated was homogeneous in analytical disc electrophoresis and showed a single protein component with a molecular weight of 26 300 in dodecylsulfate-electrophoresis. There are similarities in the amino acid compositions of human and porcine pancreatic elastases. 4) The human enzyme has a lower activity on elastin than porcine elastase but similar activities on casein and fibrin. The Km value for Boc-Ala-ONp was 5.13 X 10(-4) M. The elastase isolated was 98% active, as judged from active site titration. 5) The results of immunodiffusion studies of activated pancreatic juice and duodenal juice with specific elastase-directed antibodies indicate that the purified enzyme was the single elastolytic enzyme present. 6) It is a cationic protein without any carbohydrate. The activation of the pro-elastase resulted in the formation of an active enzyme with a higher isoelectric point than the zymogen.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D007611:Aprotinin; D004386:Duodenum; D006098:Granulocytes / Q000201:enzymology; D006801:Humans; D005779:Immunodiffusion; D007700:Kinetics; D010196:Pancreatic Elastase / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D010189:Pancreatic Juice / Q000201:enzymology*; D011817:Rabbits; D013552:Swine
chemical_list: D000596:Amino Acids; D007611:Aprotinin; D010196:Pancreatic Elastase