Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB)

Enzyme Nomenclature. Recommendations 1992

Supplement 4: corrections and additions (1997)

Prepared on behalf of the advisory panel on peptidase nomenclature by Alan J. BARRETT, The Babraham Institute, Cambridge CB2 4AT, England

This supplement is as close as possible to the published version [see Eur. J. Biochem., 1997, 250, 1-6]. If you need to cite this supplement please quote this references as its source.

This document contains further additions and amendments to Enzyme Nomenclature (1992), published by Academic Press, San Diego, California, ISBN 0-12-227164-5 (hardback), 0-12-227165-3 (paperback). Supplements 1, 2 and 3 were published in Eur. J. Biochem. 223, 1-5 (1994), Eur. J. Biochem. 232, 1-6, 1995 and Eur. J. Biochem. 237, 1-5, 1996. The entries marked with an asterisk are revisions of pre-existing entries. Families of peptidases are referred to by use of the numbering system of Rawlings, N.D. & Barrett, A.J. (Methods Enzymol. 244, 19-61 and 461-486, 1994; Methods Enzymol. 248, 105-120 and 183-228, 1995). The full, amended text of Enzyme Nomenclature 1992 may be found on the Internet at Comments and suggestions on enzyme classification and nomenclature may be sent to Prof. K. F. Tipton, Department of Biochemistry, Trinity College Dublin, Dublin 2, Ireland.


amastatin Leu[1ψ2,CHOHCONH]ValValAsp

arphamenine A Arg[1ψ2,COCH2]Phe

arphamenine B Arg[1ψ2,COCH2]Tyr

bestatin Phe[1ψ2,CHOHCONH]Leu

quisqualic acid 3-(3,5-dioxo-1,2,4-oxazadiazolidin-2-yl)Ala


Recommended name: Aminopeptidase B

Reaction: Release of N-terminal Arg and Lys from oligopeptides when P1' is not Pro. Also acts on arylamides of Arg and Lys

Other names: Arylamidase II; Arginine aminopeptidase; Arginyl aminopeptidase; Cl--Activated arginine aminopeptidase; Cytosol aminopeptidase IV

Comments: Cytosolic or membrane-associated enzyme from mammalian tissues, activated by 0.15 M Cl- and low concentrations of thiol compounds. Hydrolyses a non-peptide (epoxide) bond in leukotriene A4, but is distinct from leukotriene-A4 hydrolase (EC [5]. Potently inhibited by arphamenine B, and also inhibited by chelating agents, N-ethylmaleimide, arphamenine A, amastatin and bestatin. A zinc metallopeptidase in family M1 [4,5]


1. Gainer, H., Russell, J.T. & Loh, Y.P. (1984) An aminopeptidase activity in bovine pituitary secretory vesicles that cleaves the N-terminal arginine from beta-lipotropin(60-65). FEBS Lett. 175, 135-139

2. Belhacène, N., Mari, B., Rossi, B. & Auberger, P. (1993) Characterization and purification of T lymphocyte aminopeptidase B: a putative marker of T cell activation. Eur. J. Immunol. 23, 1948-1955

3. Cadel, S., Pierotti, A.R., Foulon, T., Créminon, C., Barré, N., Segrétain, D. & Cohen, P. (1995) Aminopeptidase-B in the rat testes: Isolation, functional properties and cellular localization in the seminiferous tubules. Mol. Cell. Endocrinol. 110, 149-160

4. Fukasawa, K.M., Fukasawa, K., Kanai, M., Fujii, S. & Harada, M. (1996) Molecular cloning and expression of rat liver aminopeptidase B. J. Biol. Chem. 271, 30731-30735

5. Cadel, S., Foulon, T., Viron, A., Balogh, A., Midol-Monnet, S., Noel, N. & Cohen, P. (1997) Aminopeptidase B from the rat testis is a bifunctional enzyme structually related to leukotriene-A4 hydrolase. Proc. Natl. Acad. Sci. USA 94, 2963-2968

[ Deleted entry: Thermophilic aminopeptidase]


Recommended name: Aminopeptidase Y

Reaction: Preferentially, release of N-terminal lysine

Other Names: Aminopeptidase Co; Aminopeptidase (cobalt-activated); Lysyl aminopeptidase

Comments: Requires Co2+; inhibited by Zn2+ and Mn2+. An enzyme best known from Saccharomyces cerevisiae that hydrolyses Lys-NHPhNO2 and, more slowly, Arg-NHPhNO2. In peptidase family M28


1. Achstetter, T., Ehmann, C. & Wolf, D.H. (1982) Aminopeptidase Co, a new yeast peptidase. Biochem. Biophys. Res. Commun. 109, 341-347

2. Yasuhara, T., Nakai, T. & Ohashi, A. (1994) Aminopeptidase Y, a new aminopeptidase from Saccharomyces cerevisiae. Purification, properties, localization, and processing by protease B. J. Biol. Chem. 269, 13644-13650

3. Nishizawa, M., Yasuhara, T., Nakai, T., Fujiki, Y. & Ohashi, A. (1994) Molecular cloning of the aminopeptidase Y gene of Saccharomyces cerevisiae. Sequence analysis and gene disruption of a new aminopeptidase. J. Biol. Chem. 269, 13651-13655


Recommended name: Aminopeptidase I

Reaction: Release of an N-terminal amino acid, preferably a neutral or hydrophobic one, from a polypeptide. Aminoacyl-arylamides are poor substrates

Other names: Aminopeptidase III; Aminopeptidase yscI; Leucine aminopeptidase IV; Yeast aminopeptidase I

Comments: A 640-kDa, dodecameric enzyme best known as the major vacuolar aminopeptidase of yeast, Saccharomyces cervisiae, in which species it was first given the name aminopeptidase I (one), amongst others. Activity is stimulated by both Zn2+ and Cl- ions. In peptidase family M18


1. Johnson, M.J. (1941) Isolation and properties of a pure yeast polypeptidase. J. Biol. Chem. 137, 575-586

2. Metz, G. & Rohm, K.-H. (1976) Yeast aminopeptidase I. Chemical composition and catalytic properties. Biochim. Biophys. Acta 429, 933-949

3. Chang, Y-H. & Smith, J.A. (1989) Molecular cloning and sequencing of genomic DNA encoding aminopeptidase I from Saccharomyces cervisiae. J. Biol. Chem. 264, 6979-6983

4. Oda, M.N., Scott, S.V., Hefner-Gravink, A., Caffarelli, A.D. & Klionsky, D.J. (1996) Identification of a cytoplasm to vacuole targeting determinant in aminopeptidase I. J. Cell Biol. 132, 999-1010

[ Transferred entry: now EC - Membrane alanyl aminopeptidase]


Recommended name: Carboxypeptidase U

Reaction: Release of C-terminal Arg and Lys from a polypeptide

Other names: Arginine carboxypeptidase; Carboxypeptidase R; Plasma carboxypeptidase B (misleading, since the term carboxypeptidase B is used for other enzymes); Thrombin-activatable fibrinolysis inhibitor

Comments: Pro-carboxypeptidase U in (human) plasma is activated by thrombin or plasmin during clotting to form the unstable carboxypeptidase U, with activity similar to that of the more stable, lysine carboxypeptidase, except that no preference is shown for Lys over Arg. A zinc enzyme, in peptidase family M14


1. Eaton, D.L., Malloy, B.E., Tsai, S.P., Henzel, W. & Drayna, D. (1991) Isolation, molecular cloning, and partial characterization of a novel carboxypeptidase B from human plasma. J. Biol. Chem. 266, 21833-21838

2. Shinohara, T., Sakurada, C., Suzuki, T., Takeuchi, O., Campbell, W., Ikeda, S., Okada, N. & Okada, H. (1994) Pro-carboxypeptidase R cleaves bradykinin following activation. Int. Arch. Allergy Immunol. 103, 400-404

3. Wang, W., Hendriks, D.F. & Scharpé, S. (1994) Carboxypeptidase U, a plasma carboxypeptidase with high affinity for plasminogen. J. Biol. Chem. 269, 15937-15944

4. Tan, A.K. & Eaton, D.L. (1995) Activation and characterization of procarboxypeptidase B from human plasma. Biochemistry 34, 5811-5816

5. Broze, G.J., Jr. & Higuchi, D.A. (1996) Coagulation-dependent inhibition of fibrinolysis: Role of carboxypeptidase U and the premature lysis of clots from hemophilic plasma. Blood 88, 3815-3823


Recommended name: Glutamate carboxypeptidase II

Reaction: Release of an unsubstituted, C-terminal glutamyl residue, typically from Ac-Asp-Glu or folylpoly-γ-glutamates

Other names: N-Acetylated-α-linked-acidic dipeptidase (NAALADase); Prostate-specific membrane antigen

Comments: A metallo-carboxypeptidase that is predominantly expressed as a membrane-bound enzyme of 94-100 kDa [2,3,5], but also exists in a soluble form. Hydrolyses α-peptide bonds in Ac-Asp-Glu [1-3], Asp-Glu [1], and Glu-Glu [1], but also γ-glutamyl bonds in γ-Glu-Glu [1], and folylpoly-γ-glutamates [4]. With folylpoly-γ-glutamates, shows processive carboxypeptidase activity to produce pteroylmonoglutamate [4]. Does not hydrolyse Ac-β-Asp-Glu [1]. Known inhibitors: quisqualic acid [1,2], Ac-β-Asp-Glu [1], and 2-phosphonomethyl-pentanedioate. Appears to require a carboxylate moiety in the S1 subsite [1,2]. The release of C-terminal glutamate from folylpoly-γ-glutamates is also catalysed by pteroyl-γ-glutamate carboxypeptidase (EC and γ-Glu-X carboxypeptidase (EC In peptidase family M28 [5]


1. Serval, V., Barbeito, L., Pittaluga, A., Cheramy, A., Lavielle, S. & Glowinski, J. (1990) Competitive inhibition of N-acetylated-alpha-linked acidic dipeptidase activity by N-acetyl-L-aspartyl-beta-linked L-glutamate. J. Neurochem. 55, 39-46

2. Slusher, B.S., Robinson, M.B., Tsai, G.C., Simmons, M.L., Richards, S.S. & Coyle, J.T. (1990) Rat brain N-acetylated α-linked acidic dipeptidase activity. Purification and immunological characterization. J. Biol. Chem. 265, 21297-21301

3. Carter, R.E., Feldman, A.R. & Coyle, J.T. (1996) Prostate-specific membrane antigen is a hydrolase with substrate and pharmacologic characteristics of a neuropeptidase. Proc. Natl. Acad. Sci. U. S. A. 93, 749-753

4. Pinto, J.T., Suffoletto, B.P., Berzin, T.M., Qiao, C.H., Lin, S.L., Tong, W.P., May, F., Mukherjee, B. & Heston, W.D.W. (1996) Prostate-specific membrane antigen - a novel folate hydrolase in human prostatic-carcinoma cells. Clinical Cancer Research 2, 1445-1451

5. Rawlings, N.D. & Barrett, A.J. (1997) Structure of membrane glutamate carboxypeptidase. Biochim. Biophys. Acta 1339, 247-252


Recommended name: Metallocarboxypeptidase D

Reaction: Releases C-terminal Arg and Lys from polypeptides

Other names: Carboxypeptidase D (cattle, human, mouse, rat); gp180 (duck)

Comments: Activated by Co2+; inhibited by guanidinoethylmercaptosuccinic acid. Large molecule (180 kDa) because of presence of three copies of metallopeptidase domain. The product of the silver gene (Drosophila) is similar. A zinc metallopeptidase in family M14


1. Kuroki, K., Eng, F., Ishikawa, T., Turck, C., Harada, F. & Ganem, D. (1995) gp180, a host cell glycoprotein that binds duck hepatitis B virus particles, is encoded by a member of the carboxypeptidase gene family. J. Biol. Chem. 270, 15022-15028.

2. Song, L.X. & Fricker, L.D. (1995) Purification and characterization of carboxypeptidase D, a novel carboxypeptidase E-like enzyme, from bovine pituitary. J. Biol. Chem. 270, 25007-25013

3. Song, L.X. & Fricker, L.D. (1996) Tissue distribution and characterization of soluble and membrane-bound forms of metallocarboxypeptidase D. J. Biol. Chem. 271, 28884-28889


Recommended name: Pyroglutamyl-peptidase I

Reaction: Release of an N-terminal pyroglutamyl group from a polypeptide, the second amino acid generally not being Pro

Other Names: 5-Oxoprolyl-peptidase; Pyrase; Pyroglutamate aminopeptidase; Pyroglutamyl aminopeptidase; L-Pyroglutamyl peptide hydrolase; Pyrrolidone-carboxyl peptidase; Pyrrolidone-carboxylate peptidase; Pyrrolidonyl peptidase

Comments: A cysteine peptidase, known from bacteria, plants and animals. The enzyme from bacterial sources is used in protein sequencing, and is in peptidase family C15. Formerly EC


1. Tsuru, D., Nakamura, K., Yoshimoto, T. & Fujiwara, K. (1984) Pyroglutamyl-peptidase from Bacillus amyloliquefaciens. An improved purification method and some properties of the enzyme. Biochim. Biophys. Acta 791, 117-122

2. Awadé, A.C., Cleuziat, P., Gonzalès, T. & Robert-Baudouy, J. (1994) Pyrrolidone carboxyl peptidase (Pcp): an enzyme that removes pyroglutamic acid (pGlu) from pGlu-peptides and pGlu-proteins. Proteins: Struct. Funct. Genet. 20, 34-51

3. Patti, J.M., Schneider, A., Garza, N. & Boles, J.O. (1995) Isolation and characterization of pcp, a gene encoding a pyrrolidone carboxyl peptidase in Staphylococcus aureus. Gene 166, 95-99

4. Le Saux, O., Gonzalès, T. & Robert-Baudouy, J. (1996) Mutational analysis of the active site of Pseudomonas fluorescens pyrrolidone carboxyl peptidase. J. Bacteriol. 178, 3308-3313


Recommended name: β-Aspartyl peptidase

Reaction: Cleavage of a β-linked Asp residue from the N-terminus of a polypeptide

Comments: Other isopeptide bonds, e.g. γ-glutamyl and β-alanyl, are not hydrolysed. A mammalian, cytosolic enzyme. Formerly EC


1. Haley, E.E. (1970) β-Aspartyl peptidase from rat liver. Methods Enzymol. 19, 737-741


Recommended name: γ-Glutamyl hydrolase

Reaction: Hydrolysis of a γ-glutamyl bond

Other Names: Conjugase; Folate conjugase; Lysosomal γ-glutamyl carboxypeptidase; γ-Glu-X carboxypeptidase; Pteroyl-poly-γ-glutamate hydrolase

Comments: A lysosomal or secreted, thiol-dependent peptidase, most active at acidic pH. Commonly studied with folylpoly-γ-glutamate as substrate, with which the initial cleavage may release glutamate or poly-γ-glutamate of two or more residues, according to the species of origin of the enzyme. Final products are pteroyl-α-glutamate (folic acid) and free glutamate. Highly specific for the γ-glutamyl bond, but not for the C-terminal amino acid (leaving group). Action on γ-glutamyl bonds is independent of an N-terminal pteroyl moiety, but it is not known whether an N-terminal γ-Glu residue can be hydrolysed. In peptidase family C26. Formerly EC


1. McGuire, J.J. & Coward, J.K. (1984) Pteroylpolyglutamates: biosynthesis, degradation and function. In: Folates and Pterins (Blakley, R.L. & Benkovic, S.J., eds.) pp. 135-191, John Wiley & Sons, New York

2. Wang, Y., Nimec, Z., Ryan, T.J., Dias, J.A. & Galivan, J. (1993) The properties of the secreted gamma-glutamyl hydrolases from H35 hepatoma cells. Biochim. Biophys. Acta 1164, 227-235

3. Yao, R., Rhee, M.S. & Galivan, J. (1995) Effects of gamma-glutamyl hydrolase on folyl and antifolylpolyglutamates in cultured H35 hepatoma cells. Mol. Pharmacol. 48, 505-511

4. Yao, R., Schneider, E., Ryan, T.J. & Galivan, J. (1996) Human gamma-glutamyl hydrolase: Cloning and characterization of the enzyme expressed in vitro. Proc. Natl. Acad. Sci. U. S. A. 93, 10134-10138

5. Yao, R., Nimec, Z., Ryan, T.J. & Galivan, J. (1996) Identification, cloning, and sequencing of a cDNA coding for rat gamma-glutamyl hydrolase. J. Biol. Chem. 271, 8525-8528

[ Transferred entry: now EC - N-Acetylmuramoyl-L-alanine amidase]


Recommended name: Snake venom factor V activator

Reaction: Fully activates human clotting factor V by a single cleavage at the Trp-Tyr-Leu-Arg1545Ser-Asn-Asn-Gly bond. Cattle, but not rabbit, factor V is cleaved, and no other proteins of the clotting system are attacked. Esterase activity is observed on Bz-Arg- OEt and Tos-Arg- OMe, and amidase activity on Phe-pipecolyl-Arg-NHPhNO2

Comment: Known from venom of Vipera russelli. Inhibited by di-isopropyl fluorophosphate, unlike the metallopeptidase russellysin (EC that is specific for factor X [1]. In peptidase family S1 [2]


1. Kisiel, W. & Canfield, W. M. (1981) Snake venom proteases that activate blood-coagulation factor V. Methods Enzymol. 80, 275-285

2. Tokunaga, F., Nagasawa, K., Tamura, S., Miyata, T., Iwanaga, S. & Kisiel, W. (1988) The factor V-activating enzyme (RVV-V) from Russell's viper venom. Identification of isoproteins RVV-Vα, -Vβ and -Vγ and their complete amino acid sequences. J. Biol. Chem. 263, 17417-17481


Recommended name: Lactocepin

Activity: Endopeptidase activity with very broad specificity, although some subsite preferences have been noted, e.g. large hydrophobic residues in the P1 and P4 positions, and Pro in the P2 position [1,2] Best known for its action on caseins, although it has been shown to hydrolyse haemoglobin and oxidised insulin B chain

Other names: CEP; Extracellular lactococcal proteinase; Lactococcal cell wall-associated proteinase; Lactococcal cell envelope-associated proteinase; Lactococcal proteinase; PrtP

Comments: Associated with the cell envelope of Lactococcus lactis and attached via a C-terminal membrane anchor sequence. Responsible for the hydrolysis of casein in milk and the provision of peptides essential to cell growth. Important in cheese making and the production of lactic casein, being required for rapid growth to high cell densities with concomitant production of adequate levels of lactic acid. Specificity differences between lactocepins from different starter strains may be partly responsible for imparting different flavour qualities to cheese [4]. In peptidase family S8


1. Visser, S., Robben, A.J.P.M. & Slangen, C.J. (1991) Specificity of a cell-envelope-located proteinase (PIII-type) from Lactococcus lactis subsp. cremoris AM1 in its action on bovine beta-casein. Appl. Microbiol. Biotechnol. 35, 477-483

2. Monnet, V., Ley, J.P. & Gonzalez, S. (1992) Substrate specificity of the cell envelope-located proteinase of Lactococcus lactis subsp. lactis NCDO763. Int. J. Biochem. 24, 707-718

3. Exterkate, F.A., Alting, A.C. & Bruinenberg, P.G. (1993) Diversity of cell envelope proteinase specificity among strains of Lactococcus lactis and its relationship to charge characteristics of the substrate-binding region. Appl. Environ. Microbiol. 59, 3640-3647

4. Pritchard, G.G. & Coolbear, T. (1993) The physiology and biochemistry of the proteolytic system in lactic acid bacteria. FEMS Microbiol. Rev. 12, 179-206


Recommended name: Caspase-1

Reaction: Release of interleukin 1β by specific cleavage at -Asp116Ala- and -Asp27Gly- bonds in precursor. Also hydrolyses the small-molecule substrate, Ac-Tyr-Val-Ala-AspNHMec

Other names: Interleukin 1β-converting enzyme

Comments: From mammalian monocytes. Inhibited by Ac-Tyr-Val-Ala-Asp-CHN2. In peptidase family C14


1. Howard, A., Kostura, M.J., Thornberry, M., Ding, G.J.F., Limjuco, G., Weidner, J., Salley, J.P., Hogquist, K.A., Chaplin, D.D., Mumford, R.A., Schmidt, J.A. & Tocci, M.J. (1991) IL-1 converting enzyme requires aspartic acid residues for processing of the IL-1β precursor at two distinct sites and does not cleave 31-kDa IL-1α. J. Immunol. 147, 2964-2969

2. Thornberry, N.A., Bull, H.G., Calaycay, J.R., Chapman, K.T., Howard, A.D., Kostura, M.J., Miller, D.K., Molineaux, S.M., Weidner, J.R., Aunins, J., Elliston, K.O., Ayala, J.M., Casano, F J., Chin, J., Ding, G.J.-F., Egger, L.A., Gaffney, E.P., Limjuco, G., Palyha, O.C., Raju, S.M., Rolando, A.M., Salley, J.P., Yamin, T.-T. & Tocci, M.J. (1992) A novel heterodimeric cysteine protease is required for interleukin-1β processing in monocytes. Nature 356, 768-774

3. Thornberry, N.A. (1994) Interleukin-1β converting enzyme. Methods Enzymol. 244, 615-631

4. Alnemri, E.S., Livingston, D.J., Nicholson, D.W., Salvesen, G., Thornberry, N.A., Wong, W.W. & Yuan, J.Y. (1996) Human ICE/CED-3 protease nomenclature. Cell 87, 171

5. Margolin, N., Raybuck, S.A., Wilson, K.P., Chen, W.Y., Fox, T., Gu, Y. & Livingston, D.J. (1997) Substrate and inhibitor specificity of interleukin-1β-converting enzyme and related caspases. J. Biol. Chem. 272, 7223-7228


Recommended name: Cathepsin K

Reaction: Broad proteolytic activity. With small-molecule substrates and inhibitors, the major determinant of specificity is P2, which is preferably Leu, Met > Phe, and not Arg

Other names: Cathepsin O and Cathepsin X (both misleading, having been used for other enzymes); Cathepsin O2

Comments: Prominently expressed in mammalian osteoclasts, and believed to play a role in bone resorption. In peptidase family C1


1. Inaoka, T., Bilbe, G., Ishibashi, O., Tezuka, K., Kumegawa, M. & Kokubo, T. (1995) Molecular cloning of human cDNA for cathepsin K: Novel cysteine proteinase predominantly expressed in bone. Biochem. Biophys. Res. Commun. 206, 89-96

2. Bossard, M.J., Tomaszek, T.A., Thompson, S.K., Amegadzie, B.Y., Hanning, C.R., Jones, C., Kurdyla, J.T., McNulty, D.E., Drake, F.H., Gowen, M. & Levy, M.A. (1996) Proteolytic activity of human osteoclast cathepsin K - Expression, purification, activation, and substrate identification. J. Biol. Chem. 271, 12517-12524

3. Bromme, D., Klaus, J.L., Okamoto, K., Rasnick, D. & Palmer, J.T. (1996) Peptidyl vinyl sulphones: A new class of potent and selective cysteine protease inhibitors - S2P2 specificity of human cathepsin O2 in comparison with cathepsins S and L. Biochem. J. 315, 85-89

4. Zhao, B.G., Janson, C.A., Amegadzie, B.Y., D'Alessio, K., Griffin, C., Hanning, C.R., Jones, C., Kurdyla, J., McQueney, M., Qiu, X.Y., Smith, W.W. & Abdel-Meguid, S.S. (1997) Crystal structure of human osteoclast cathepsin K complex with E-64. Nature Struct. Biol. 4, 109-111

5. McGrath, M.E., Klaus, J.L., Barnes, M.G. & Brömme, D. (1997) Crystal structure of human cathepsin K complexed with a potent inhibitor. Nature Struct. Biol. 4, 105-109


Recommended name: Phytepsin

Reaction: Prefers hydrophobic residues Phe, Val, Ile, Leu, and Ala at P1 and P1', but also cleaves -PheAsp- and -AspAsp- bonds in 2S albumin from plant seeds

Comments: Known particularly from barley grain, but present in other plants also. In peptidase family A1, but structurally distinct in containing an internal region of about 100 amino acids not present in other homologues of pepsin A


1. Runeberg-Roos, P., Törmäkangas, K. & Östman, A. (1991) Primary structure of a barley-grain aspartic proteinase. A plant aspartic proteinase resembling mammalian cathepsin D. Eur. J. Biochem. 202, 1021-1027

2. Kervinen, J., Sarkkinen, P., Kalkkinen, N., Mikola, L. & Saarma, M. (1993) Hydrolytic specificity of the barley grain aspartic proteinase. Phytochemistry 32, 799-803

3. Asakura, T., Watanabe, H., Abe, K. & Arai, S. (1995) Rice aspartic proteinase, oryzasin, expressed during seed ripening and germination, has a gene organization distinct from those of animal and microbial aspartic proteinases. Eur. J. Biochem. 232, 77-83

4. Kervinen, J., Törmäkangas, K., Runeberg-Roos, P., Guruprasad, K., Blundell, T. & Teeri, T.H. (1995) Structure and possible function of aspartic proteinases in barley and other plants. Adv. Exp. Med. Biol. 362, 241-254


Recommended name: Vibriolysin

Reaction: Preferential cleavage of bonds with bulky hydrophobic groups in P2 and P1'. Phe at P1' is the most favoured residue, which distinguished this enzyme from thermolysin

Other Names: Aeromonas proteolytica neutral proteinase; Aeromonolysin

Comments: Thermostable enzyme from Vibrio proteolyticus (formerly Aeromonas proteolytica). Specificity related to, but distinct from, those of thermolysin and bacillolysin [1]. A zinc metallopeptidase in family M4. Formerly included in EC


1. Holmquist, B. & Vallee, B.L. (1976) Esterase activity of zinc neutral proteases. Biochemistry 15, 101-107

2. Wilkes, S.H. & Prescott, J.M. (1976) Aeromonas neutral protease. Methods Enzymol. 45, 404-415

3. Bayliss, M.E., Wilkes, S.H. & Prescott, J.M. (1980) Aeromonas neutral protease: specificity toward extended substrates. Arch. Biochem. Biophys. 204, 214-219

4. Wilkes, S.H., Bayliss, M.E. & Prescott, J.M. (1988) Critical ionizing groups in Aeromonas neutral protease. J. Biol. Chem. 263, 1821-1825

5. David, V.A., Deutch, A.H., Sloma, A., Pawlyk, D., Ally, A. & Durham, D.R. (1992) Cloning, sequencing and expression of the gene encoding the extracellular neutral protease, vibriolysin, of Vibrio proteolyticus. Gene 112, 107-112


Recommended name: Fragilysin

Reaction: Broad proteolytic specificity, bonds hydrolysed including -GlyLeu-, -MetLeu-, -PheLeu-, -CysLeu-, LeuGly

Other names: Bacteroides fragilis (entero)toxin

Comments: Thought to be a cause of diarrhoea in animals and humans. Hydrolyses extracellular matrix proteins, and disrupts tight junctions of intestinal epithelial cells. Also degrades intracellular, cytoskeletal proteins actin, myosin and others. In peptidase family M10


1. Moncrief, J.S., Obiso, R., Jr., Barroso, L.A., Kling, J.J., Wright, R.L., Van Tassell, R.L., Lyerly, D.M. & Wilkins, T.D. (1995) The enterotoxin of Bacteroides fragilis is a metalloprotease. Infect. Immun. 63, 175-181

2. Obiso, R.J., Jr., Lyerly, D.M., Van Tassell, R.L. & Wilkins, T.D. (1995) Proteolytic activity of the Bacteroides fragilis enterotoxin causes fluid secretion and intestinal damage in vivo. Infect. Immun. 63, 3820-3826

3. Donelli, G., Fabbri, A. & Fiorentini, C. (1996) Bacteroides fragilis enterotoxin induces cytoskeletal changes and surface blebbing in HT-29 cells. Infect. Immun. 64, 113-119

4. Koshy, S.S., Montrose, M.H. & Sears, C.L. (1996) Human intestinal epithelial cells swell and demonstrate actin rearrangement in response to the metalloprotease toxin of Bacteroides fragilis. Infect. Immun. 64, 5022-5028

5. Kling, J.J., Wright, R.L., Moncrief, J.S. & Wilkins, T.D. (1997) Cloning and characterization of the gene for the metalloprotease enterotoxin of Bacteroides fragilis. FEMS Microbiol. Lett. 146, 279-284


Recommended name: Lysostaphin

Reaction: Hydrolysis of the -GlyGly- bond in the pentaglycine inter-peptide link joining staphylococcal cell wall peptidoglycans

Other Names: Glycyl-glycine endopeptidase

Comments: A zinc-dependent, 25-kDa endopeptidase from Staphylococcus simulans. Lyses cells of S. aureus, in particular, by its action on the cross-bridges of the cell wall. In peptidase family M37


1. Recsei, P.A., Gruss, A.D. & Novick, R.P. (1987) Cloning, sequence, and expression of the lysostaphin gene from Staphylococcus simulans. Proc. Natl. Acad. Sci. U.S.A. 84, 1127-1131

2. Baba, T. & Schneewind, O. (1996) Target cell specificity of a bacteriocin molecule: A C-terminal signal directs lysostaphin to the cell wall of Staphylococcus aureus. EMBO J. 15, 4789-4797

3. Thumm, G. & Götz, F. (1997) Studies on prolysostaphin processing and characterization of the lysostaphin immunity factor (Lif) of Staphylococcus simulans biovar staphylolyticus. Mol. Microbiol. 23, 1251-1265

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