ExplorEnz: EC 3.4.26.2

Your query returned 1 entry. Printable version

3.4.26.2

Accepted name:

scytalidoglutamic peptidase

Reaction:

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.

Other name(s):

scytalidopepsin-B; SCP-B; SGP; scytalidocarboxylpeptidase-B

Comments:

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).

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Kataoka, Y., Takada, K., Oyama, H., Tsunemi, M., James, M.N. and Oda, K. Catalytic residues and substrate specificity of scytalidoglutamic peptidase, the first member of the eqolisin in family (G1) of peptidases. FEBS Lett. 579 (2005) 2991–2994. [DOI] [PMID: 15907842]
2.	Fujinaga, M., Cherney, M.M., Oyama, H., Oda, K. and James, M.N. The molecular structure and catalytic mechanism of a novel carboxyl peptidase from Scytalidium lignicolum. Proc. Natl. Acad. Sci. USA 101 (2004) 3364–3369. [DOI] [PMID: 14993599]
3.	Pillai, B., Cherney, M.M., Hiraga, K., Takada, K., Oda, K. and James, M.N. Crystal structure of scytalidoglutamic peptidase with its first potent inhibitor provides insights into substrate specificity and catalysis. J. Mol. Biol. 365 (2007) 343–361. [DOI] [PMID: 17069854]
4.	Kondo, M.Y., Okamoto, D.N., Santos, J.A., Juliano, M.A., Oda, K., Pillai, B., James, M.N., Juliano, L. and Gouvea, I.E. Studies on the catalytic mechanism of a glutamic peptidase. J. Biol. Chem. 285 (2010) 21437–21445. [DOI] [PMID: 20442413]

[EC 3.4.26.2 created 2023]