Beauvais A, Monod M, Debeaupuis J P, Diaquin M, Kobayashi H, Latgé J P
Laboratoire des Aspergillus, Institut Pasteur, Paris, France.
J Biol Chem. 1997 Mar 7;272(10):6238-44. doi: 10.1074/jbc.272.10.6238.
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.
从烟曲霉培养基中纯化出一种新型二肽基肽酶（DPP V）。这是关于分泌型二肽基肽酶的首次报道。该酶分子量为88 kDa，含有约9 kDa的N - 连接碳水化合物。二肽基肽酶的表达和分泌随生长条件而变化；当培养基在无糖情况下仅含有蛋白质或蛋白水解物时，检测到细胞内和细胞外水平最高。DPP V基因被克隆，与其他真核二肽基肽酶基因具有显著的序列同源性。与其他均为细胞内的二肽基肽酶不同，DPP V含有信号肽。与其他二肽基肽酶的基因一样，DPP V的基因显示出非经典丝氨酸蛋白酶催化位点的共有序列。在毕赤酵母中获得的天然和重组DPP V的生化特性独特，其底物特异性仅限于在最适中性pH下对X - Ala、His - Ser和Ser - Tyr二肽的水解。此外我们还表明，DPP V与用于曲霉病诊断的两种主要抗原之一相同。
