title: The two human chymotrypsinogens. Purification and characterization.
abstract: The two chymotrypsinogens present in human pancreatic juice have been purified and characterized. The zymogens are two immunologically and electrophoretically different proteins. Chymotrypsinogen A, the major chymotryptic component (90% of the total potential N-acetyl-L-tyrosine ethylester activity) is stable in acidic medium. By its molecular weight (approx. 24 000), specific activity (530) and amino acid composition, human chymotrypsinogen A resembles chymotrypsinogens A and B form bovine and porcine pancreas. Chymotrypsinogen B is a minor chymotryptic component (7% of the total potential N-acetyl-L-tyrosine ethylester activity) unstable in acidic medium with a molecular weight slightly higher (approx. 27 000) and a specific activity slightly lower (300) than chymotrypsinogen A. The last 3% of the total potential N-acetyl-L-tyrosine ethylester activity corresponds to a proelastase that we have partially characterized.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D002919:Chymotrypsinogen / Q000302:isolation & purification / Q000378:metabolism; D004355:Drug Stability; D004589:Electrophoresis, Disc; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007122:Immunoelectrophoresis; D007527:Isoenzymes / Q000302:isolation & purification / Q000378:metabolism; D007700:Kinetics; D008970:Molecular Weight; D010179:Pancreas / Q000201:enzymology; D013045:Species Specificity
chemical_list: D000596:Amino Acids; D007527:Isoenzymes; D002919:Chymotrypsinogen