Biochemical and Antigenic Characterization of a New Dipeptidyl-Peptidase Isolated from Aspergillus fumigatus

Abstract

A novel dipeptidyl-peptidase (DPP V) was purified from the culture medium of Aspergillus fumigatus. This is the first report of a secreted dipeptidyl-peptidase. The enzyme had a molecular mass of 88 kDa and contained approximately 9 kDa of N-linked carbohydrate. The expression and secretion of dipeptidyl-peptidase varied with the growth conditions; maximal intra-and extracellular levels were detected when the culture medium contained only proteins or protein hydrolysates in the absence of sugars. The gene of DPP V was cloned and showed significant sequence homology to other eukaryotic dipeptidyl-peptidase genes. Unlike the other dipeptidyl-peptidases, which are all intracellular, DPP V contained a signal peptide. Like the genes of other dipeptidyl-peptidases, that of DPP V displayed the consensus sequences of the catalytic site of the nonclassical serine proteases. The biochemical properties of native and recombinant DPP V obtained in Pichia pastoris were unique and were characterized by a substrate specificity limited to the hydrolysis of X-Ala, His-Ser, and Ser-Tyr dipeptides at a neutral pH optimum. In addition, we showed that DPP V is identical to one of the two major antigens used for the diagnosis of aspergillosis.

Identification and Characterization of Prokaryotic Dipeptidyl-peptidase 5 from Porphyromonas gingivalis

“…7), which is identical to that of A. fumigatus DPP5 (38). The pH optimum of DPP7 was slightly shifted to basic pH around 7 and that of DPP4 was further to pH 7.5 in consistent to previous studies (21,22).…”

“…2C) and we also found that it shares a 28.5% amino acid sequence identity with another S9 family member, Aspergillus fumigatus DPP5 (38). This homology value is even higher than that of Pro-specific P. gingivalis DPP4 (14.2%) and PTP-A (14.8%) (Fig.…”

Production and characterization of two major Aspergillus oryzae secreted prolyl endopeptidases able to efficiently digest proline-rich peptides of gliadin

“…During this process, the main function of endoproteases is to produce a large number of free ends on which exoproteases may act. Exoproteases secreted at neutral or alkaline pH are leucine aminopeptidases of the M28 family and an Xprolyl exopeptidase (DppIV) of the S9 family (see MEROPS peptidase database; http://merops.sanger.ac.uk/) (Beauvais et al, 1997;Blinkovsky et al, 2000;Chien et al, 2002;Doumas et al, 1998;Monod et al, 2009). Exoproteases secreted at acidic pH are tripeptidyl peptidases of the sedolisin family and prolyl endopeptidases of the S28 family (Reichard et al, 2006;Sriranganadane et al, 2010).…”

Purification and characterization of a novel dipeptidyl peptidase from Dictyostelium discoideum

“…DPP IV (EC 3.4.14.5), a serine protease with an optimum pH of 8-9, specifically cleaves gly-pro from the N-termini of its substrates. Several DPPs, including some with specificities different from those in mammals, have recently been identified in microorganisms (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12) including Dictyostelium discoideum (13)(14)(15)(16).…”

“…DPP II (EC 3.4.14.2), a serine protease with an acidic optimum pH of 4.5-6, preferentially cleaves dipeptides from the N-termini of X-ala-or X-pro-NA. DPP III (EC 3.4.14.4) is a serine protease with an optimum pH of [8][9][10].…”