Dipeptidyl peptidase 9 is an enzyme that in humans is encoded by the DPP9gene.
This gene encodes a protein that is a member of the S9B family in clan SC of the serine proteases. The protein has been shown to have post-proline dipeptidyl aminopeptidase activity, cleaving Xaa-Pro dipeptides from the N-termini of proteins. Although the activity of this protein is similar to that of dipeptidyl peptidase 4 (DPP4), it does not appear to be membrane bound. In general, dipeptidyl peptidases appear to be involved in the regulation of the activity of their substrates and have been linked to a variety of diseases including type 2 diabetes, obesity and cancer. Several transcript variants of this gene have been described but not fully characterized.
Ajami K, Abbott CA, Obradovic M et al. (2003). "Structural requirements for catalysis, expression, and dimerization in the CD26/DPIV gene family". Biochemistry42 (3): 694–701. doi:10.1021/bi026846s. PMID12534281.CS1 maint: Explicit use of et al. (link)
Ota T, Suzuki Y, Nishikawa T et al. (2004). "Complete sequencing and characterization of 21,243 full-length human cDNAs". Nat. Genet.36 (1): 40–5. doi:10.1038/ng1285. PMID14702039.CS1 maint: Explicit use of et al. (link)
Ajami K, Abbott CA, McCaughan GW, Gorrell MD (2004). "Dipeptidyl peptidase 9 has two forms, a broad tissue distribution, cytoplasmic localization and DPIV-like peptidase activity". Biochim. Biophys. Acta1679 (1): 18–28. doi:10.1016/j.bbaexp.2004.03.010. PMID15245913.
Ogasawara W, Tanaka C, Suzuki M et al. (2005). "Isoforms of dipeptidyl aminopeptidase IV from Pseudomonas sp. WO24: role of the signal sequence and overexpression in Escherichia coli". Protein Expr. Purif.41 (2): 241–51. doi:10.1016/j.pep.2004.10.027. PMID15866709.CS1 maint: Explicit use of et al. (link)