Phe, but not Leu15-Tyr and Phe25-Tyr in the B chain of insulin
Reaction: Hydrolysis of proteins with broad specificity, cleaving Phe24Phe, but not Leu15-Tyr and Phe25-Tyr in the B chain of insulin
Other names: Scytalidium aspartic proteinase B; Ganoderma lucidum carboxyl proteinase; Ganoderma lucidum aspartic proteinase; Scytalidium lignicolum aspartic proteinase B; SLB
Comments: A second endopeptidase from Scytalidium lignicolum (see scytalidopepsin A) that is insensitive to pepstatin and methyl 2-diazoacetamidohexanoate. 1,2-Epoxy-3-(p-nitrophenoxy)propane reacts with Glu53, which replaces one of the aspartic residues at the active centre. One of the smallest aspartic endopeptidases active as the monomer, with Mr 22,000. Similarly inhibitor-resistant endopeptidases are found in the basidiomycetes Lentinus edodes [1] and Ganoderma lucidum [3], and in Polyporus tulipiferae [4], a second endopeptidase distinct from polyporopepsin, but these are of typical aspartic endopeptidase size, Mr about 36,000. Type example of peptidase family G1
Links to other databases: BRENDA, EXPASY, KEGG, MEROPS, Metacyc, PDB, CAS registry number: 104781-89-7
References:
1. Terashita, T., Oda, K., Kono, M. and Murao, S. Streptomyces pepsin inhibitor-insensitive carboxyl proteinase from Lentinus edodes. Agric. Biol. Chem. 45 (1981) 1937-1943
2. Maita, T., Nagata, S., Matsuda, G., Maruta, S., Oda, K., Murao, S. and Tsuru, D. Complete amino acid sequence of Scytalidium lignicolum acid protease B. J. Biochem. (Tokyo) 95 (1984) 465-473
3. Terashita, T., Oda, K., Kono, M. and Murao, S. Streptomyces pepsin inhibitor-insensitive carboxyl proteinase from Ganoderma lucidum. Agric. Biol. Chem. 48 (1984) 1029-1035. [PMID: 6370989]
4. Kobayashi, H., Kusakabe, I. and Murakami, K. Purification and characterization of a pepstatin-insensitive carboxyl proteinase from Polyporus tulipiferae (Irpex lacteus). Agric. Biol. Chem. 49 (1985) 2393-2397
5. Tsuru, D., Shimada, S., Maruta, S., Yoshimoto, T., Oda, K., Murao, S., Miyata, T. and Iwanaga, S. 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 (1986) 1537-1539. [PMID: 3519605]