Scytalidopepsin B

Scytalidocarboxyl peptidase B

Structure of scytalidocarboxyl peptidase B, with cleaved peptide product in black and active site glutamate-glutamine dyad side chains in red. (PDB: 1S2K​)
Identifiers
EC number 3.4.23.32
CAS number 104781-89-7
Databases
IntEnz IntEnz view
BRENDA BRENDA entry
ExPASy NiceZyme view
KEGG KEGG entry
MetaCyc metabolic pathway
PRIAM profile
PDB structures RCSB PDB PDBe PDBsum

Scytalidocarboxyl peptidase B, also known as Scytalidoglutamic peptidase and Scytalidopepsin B (EC 3.4.23.32, obsolete names include Scytalidium aspartic proteinase B, Ganoderma lucidum carboxyl proteinase, Ganoderma lucidum aspartic proteinase, Scytalidium lignicolum aspartic proteinase B, SLB) is a proteolytic enzyme.[1][2][3][4][5] It was previously thought to be an aspartic protease, but determination of the its molecular structure showed it to belong a novel group of proteases, glutamic protease.[6][7]

The protease has a unique structure and a novel catalytic dyad (E136 and Q53) in its active site. The active-site residues, glutamic acid (E) and glutamine (Q), was used to coin the name of the family of proteases, eqolisins, to which Scytalidoglutamic peptidase B belongs.[6]

This enzyme catalyses the following chemical reaction

Hydrolysis of proteins with broad specificity, cleaving Phe24-Phe and Tyr26–Thr but not Leu15-Tyr and Phe25-Tyr in the B chain of insulin. It also cleaves the His6–Pro bond of angiotensin I, the ability to cleave a peptide bond with Pro in the P1′ position is unusual.

This endopeptidase is isolated from Scytalidium lignicolum. It is an acid protease, and is most active at pH 2.0 when casein is used as substrate. Eqolosins prefer bulky amino acid residues at the P1 site and small amino acid residues at the P1′ site.[8] The substrate specificity of scytalidoglutamic peptidase is unique, particularly in the substrate preferences at the P3 (basic amino acid), P1′ (small amino acid) and P3′ (basic) positions.[9]

References

  1. ↑ Terashita, T., Oda, K., Kono, M. and Murao, S. (1981). "Streptomyces pepsin inhibitor-insensitive carboxyl proteinase from Lentinus edodes". Agric. Biol. Chem. 45: 1937–1943. doi:10.1271/bbb1961.45.1937.
  2. ↑ Maita, T., Nagata, S., Matsuda, G., Maruta, S., Oda, K., Murao, S. and Tsuru, D. (1984). "Complete amino acid sequence of Scytalidium lignicolum acid protease B". J. Biochem. (Tokyo) 95: 465–473. PMID 6370989.
  3. ↑ Terashita, T., Oda, K., Kono, M. and Murao, S. (1984). "Streptomyces pepsin inhibitor-insensitive carboxyl proteinase from Ganoderma lucidum". Agric. Biol. Chem. 48: 1029–1035. doi:10.1271/bbb1961.48.1029.
  4. ↑ Kobayashi, H., Kusakabe, I. and Murakami, K. (1985). "Purification and characterization of a pepstatin-insensitive carboxyl proteinase from Polyporus tulipiferae (Irpex lacteus)". Agric. Biol. Chem. 49: 2393–2397. doi:10.1271/bbb1961.49.2393.
  5. ↑ Tsuru, D., Shimada, S., Maruta, S., Yoshimoto, T., Oda, K., Murao, S., Miyata, T. and Iwanaga, S. (1986). "Isolation and amino acid sequence of a peptide containing an epoxide-reactive residue from the thermolysin-digest of Scytalidium lignicolum acid protease B". J. Biochem. (Tokyo) 99: 1537–1539. PMID 3519605.
  6. 1 2 Masao Fujinaga, Maia M. Cherney, Hiroshi Oyama, Kohei Oda, Michael N. G. James (2004). "The molecular structure and catalytic mechanism of a novel carboxyl peptidase from Scytalidium lignicolum". Proc Natl Acad Sci U S A. 101 (10): 3364–9. doi:10.1073/pnas.0400246101. PMID 14993599.
  7. ↑ Pillai B1, Cherney MM, Hiraga K, Takada K, Oda K, James MN. (2007). "Crystal structure of scytalidoglutamic peptidase with its first potent inhibitor provides insights into substrate specificity and catalysis". Journal of Molecular Biology 365 (2): 343–61. Epub 2006. doi:10.1016/j.jmb.2006.09.058. PMID 17069854.
  8. ↑ Kohei Oda (2012). "New families of carboxyl peptidases: serine-carboxyl peptidases and glutamic peptidases". Journal of Biochemistry 151 (1): 13-25. doi:10.1093/jb/mvr129. PMID 22016395.
  9. ↑ Kataoka Y1, Takada K, Oyama H, Tsunemi M, James MN, Oda K. (2005). "Catalytic residues and substrate specificity of scytalidoglutamic peptidase, the first member of the eqolisin in family (G1) of peptidases". FEBS Lett. 579 (14): 2991–4. doi:10.1016/j.febslet.2005.04.050. PMID 15907842.

External links

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