KEGG ENZYME: 3.4.26.2

ENZYME: 3.4.26.2

Entry

EC 3.4.26.2                 Enzyme

Name

scytalidoglutamic peptidase;
scytalidopepsin-B;
SCP-B;
SGP;
scytalidocarboxylpeptidase-B

Class

Hydrolases;
Acting on peptide bonds (peptidases);
Glutamic endopeptidases

Reaction(IUBMB)

Hydrolysis of proteins, with a strong preference for Phe or Tyr at position P1 and one of the smaller amino-acids at P1' in the sequence - P3 - P2 - P1 !P1'- P2'- P3'-. Cleaves the Tyr26-Thr27 bond in the B chain of oxidized insulin, which is not cleaved by pepsin.

Comment

The enzyme, isolated from the fungus Scytalidium lignicola and found in several other fungi, has a low pH optimum, being most active at pH 2 with casein as substrate. It differs from the pepsins (EC 3.4.23.1 and EC 3.4.23.2) in being insensitive to inhibition by pepstatin. It also differs from mammalian pepsins in showing a preference for a positively charged residue (Lys or Arg) at the P3 position. In addition to the catalytic Glu residue, a Gln residue appears to play an important role in the hydrolytic mechanism. A member of peptidase family G01, the "eqolisin" family of glutamic peptidases (G01.0001).

History

EC 3.4.26.2 created 2023

Orthology

K20743

scytalidopepsin B

Reference

1 [PMID:15907842]

Authors

Kataoka Y, Takada K, Oyama H, Tsunemi M, James MN, Oda K.

Title

Catalytic residues and substrate specificity of scytalidoglutamic peptidase, the first member of the eqolisin in family (G1) of peptidases.

Journal

FEBS Lett 579:2991-4 (2005)
DOI:10.1016/j.febslet.2005.04.050

Reference

2 [PMID:14993599]

Authors

Fujinaga M, Cherney MM, Oyama H, Oda K, James MN.

Title

The molecular structure and catalytic mechanism of a novel carboxyl peptidase from Scytalidium lignicolum.

Journal

Proc Natl Acad Sci U S A 101:3364-9 (2004)
DOI:10.1073/pnas.0400246101

Sequence

[ag:BAA92164]

Reference

3 [PMID:17069854]

Authors

Pillai B, Cherney MM, Hiraga K, Takada K, Oda K, James MN.

Title

Crystal structure of scytalidoglutamic peptidase with its first potent inhibitor provides insights into substrate specificity and catalysis.

Journal

J Mol Biol 365:343-61 (2007)
DOI:10.1016/j.jmb.2006.09.058

Sequence

[ag:BAA92164]

Reference

4 [PMID:20442413]

Authors

Kondo MY, Okamoto DN, Santos JA, Juliano MA, Oda K, Pillai B, James MN, Juliano L, Gouvea IE.

Title

Studies on the catalytic mechanism of a glutamic peptidase.

Journal

J Biol Chem 285:21437-45 (2010)
DOI:10.1074/jbc.M110.122432

Sequence

[ag:BAA92164]

Other DBs

ExplorEnz - The Enzyme Database:

3.4.26.2

IUBMB Enzyme Nomenclature:

3.4.26.2

ExPASy - ENZYME nomenclature database:

3.4.26.2

BRENDA, the Enzyme Database:

3.4.26.2

All links

Gene (2)   
   KEGG ORTHOLOGY (1)   
   KEGG GENES (1)   
All databases (2)   

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