a-Chymotrypsin 1X Crystallized from Bovine Pancreas, 10g

α-Chymotrypsin preferentially catalyzes the hydrolysis of peptide bonds involving L-isomers of tyrosine, phenylalanine, and tryptophan. It also readily acts upon amides and esters of susceptible amino acids. In addition to bonds involving aromatic amino acids, chymotrypsin catalyzes at a high rate the hydrolysis of bonds of leucyl, methionyl, asparaginyl, and glutamyl residues. A pancreas extract contains equal amounts of two forms of the zymogen: Chymotrypsinogen A, with a molecular weight of 25,000 and and isoelectric point of 9.1, and Chymotrypsinogen B (E.C.3.4.4.6), with an isoelectric point of 5.2. Together, the zymogens represent 32% of the protein content of pancreatic extracts. Dependent upon the conditions, chymotrypsinogen A may be activated to α-, π-, δ-, β-, or γ -chymotrypsin. A serine protease that hydrolyzes peptide bonds with aromatic or large hydrophobic side chains (Tyr, Trp, Phe, Met, Leu) on the carboxyl end of the bond.