IUBMB Enzyme Nomenclature


Accepted name: chymotrypsin

Reaction: Preferential cleavage: Tyr, Trp, Phe, Leu

Other names: chymotrypsins A and B; α-chymar ophth; avazyme; chymar; chymotest; enzeon; quimar; quimotrase; α-chymar; α-chymotrypsin A; α-chymotrypsin

Comments: Chymotrypsin A is formed from cattle and pig chymotrypsinogen A, several iso-forms being produced according to the number of bonds hydrolysed in the precursor. Formerly EC Chymotrypsin B, formerly EC, formed from chymotrypsinogen B, is homologous with chymotrypsin A. Enzymes with specificity similar to that of chymotrypsins A and B have been isolated from many species. In peptidase family S1 (trypsin family)

Links to other databases: BRENDA, EXPASY, GTD, KEGG, MEROPS, Metacyc, PDB, CAS registry number: 9004-07-3


1. Wilcox, P.E. Chymotrypsinogens - chymotrypsins. Methods Enzymol. 19 (1970) 64-108

2. Blow, D.M. Structure and mechanism of chymotrypsin. Acc. Chem. Res. 9 (1976) 145-152

3. Bauer, C.-A. Active centers of α-chymotrypsin and of Streptomyces griseus proteases 1 and 3. Eur. J. Biochem. 105 (1980) 565-570. [PMID: 6768556]

4. Polgár, L. Structure and function of serine proteases. In New Comprehensive Biochemistry Vol. 16, Hydrolytic Enzymes (Neuberger, A. and Brocklehurst, K. eds), pp. 159-200 (1987) Elsevier, Amsterdam

5. Tomita, N., Izumoto, Y., Horii, A., Doi, S., Yokouchi, H., Ogawa, M., Mori, T. and Matsubara, K. Molecular cloning and nucleotide sequence of human pancreatic prechymotrypsinogen cDNA. Biochem. Biophys. Res. Commun. 158 (1989) 569-575. [PMID: 2917002]

[EC created 1961 as EC and EC, transferred 1972 to EC]

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