The sedolisin (MEROPS S53) family of peptidases are a family of serine proteases structurally related to the subtilisin (S8) family. Well-known members of this family include sedolisin ("pseudomonalisin") found in Pseudomonas bacteria, xanthomonalisin ("sedolisin-B"), physarolisin as well as animal tripeptidyl peptidase I. It is also known as sedolysin or serine-carboxyl peptidase. This group of enzymes contains a variation on the catalytic triad: unlike S8 which uses Ser-His-Asp, this group runs on Ser-Glu-Asp, with an additional acidic residue Asp in the oxyanion hole.[1]
Their optimal pH is around 3. Most members of the family are produced as a precursor protein with N-terminal (InterPro: IPR015366) and sometimes C-terminal peptides that need to be cleaved off.[2]
Sedolisin (P42790, pseudomonapepsin, sedolysin) is a serine protease. It is secreted by Pseudomonas sp. 101. It performs hydrolysis of the B chain of insulin at -Glu13-Ala-, -Leu15-Tyr- and -Phe25-Tyr-, and angiotensin I at -Tyr4-Ile-. A good synthetic substrate is Lys-Pro-Ile-Glu-Phe-Phe(NO2)-Arg-Leu.[3][4][5][6]
Physarolisin (Q8MZS4, physaropepsin) is a milk-clotting enzyme. It shows preferential cleavage of Gly8-Ser in B chain of insulin most rapidly, followed by Leu11!Val, Cys(SO3H)19-Gly and Phe24-Phe.[9][10][11][12][13]
^Oda K, Sugitani M, Fukuhara K, Murao S (March 1987). "Purification and properties of a pepstatin-insensitive carboxyl proteinase from a gram-negative bacterium". Biochimica et Biophysica Acta (BBA) - General Subjects. 923 (3): 463–469. doi:10.1016/0304-4165(87)90055-9. PMID3548827.
^Oda K, Nakatani H, Dunn BM (April 1992). "Substrate specificity and kinetic properties of pepstatin-insensitive carboxyl proteinase from Pseudomonas sp. No. 101". Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology. 1120 (2): 208–214. doi:10.1016/0167-4838(92)90272-f. PMID1562589.
^Wlodawer A, Li M, Dauter Z, Gustchina A, Uchida K, Oyama H, et al. (May 2001). "Carboxyl proteinase from Pseudomonas defines a novel family of subtilisin-like enzymes". Nature Structural Biology. 8 (5): 442–446. doi:10.1038/87610. PMID11323721. S2CID16793101.
^Henney HR, Tavana G (1982). "Purification and some properties of an intracellular acid (carboxyl) proteinase from differentiating haploid cells of Physarum flavicomum". Exp. Mycol. 6: 161–170. doi:10.1016/0147-5975(82)90090-1.
^Nishii W, Ueki T, Miyashita R, Kojima M, Kim YT, Sasaki N, et al. (February 2003). "Structural and enzymatic characterization of physarolisin (formerly physaropepsin) proves that it is a unique serine-carboxyl proteinase". Biochemical and Biophysical Research Communications. 301 (4): 1023–1029. doi:10.1016/s0006-291x(03)00083-4. PMID12589815.
^Nishii W, Kuriyama H, Takahashi K (July 2003). "The Physarum polycephalum php gene encodes a unique cold-adapted serine-carboxyl peptidase, physarolisin II". FEBS Letters. 546 (2–3): 340–344. doi:10.1016/S0014-5793(03)00621-5. PMID12832065. S2CID19197020.
