Extracellular peptidase in the fungal pathogen Pseudallescheria boydii
Extracellular peptidase in the fungal pathogen Pseudallescheria boydii
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DOI：
10.1007/s00284-005-0156-1
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发表时间：
2006-07-01
影响因子：
2.6
通讯作者：
Pinto, Marcia Ribeiro
中科院分区：
文献类型：
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作者：
da Silva, Bianca Alcantara;dos Santos, Andr Luis Souza;Pinto, Marcia Ribeiro
鲍氏伪雷氏菌是一种普遍存在的丝状真菌，能够引起人类的侵袭性疾病。在本研究中，使用十二烷基硫酸钠-聚丙烯酰胺凝胶含有牛血清白蛋白作为共聚底物，我们确定了一个28 kDa的蛋白水解活性释放到胞外环境的菌丝体的鲍氏疟原虫。该肽酶在鲍氏毕赤酵母在沙氏葡萄糖培养基中生长13天期间被检测到，并在第7天达到其最大产量。28-kDa的肽酶是活跃的酸性pH值（5.5），并有其活动完全封闭的1，10-菲咯啉，一种有效的锌金属肽酶抑制剂。另外两种金属肽酶抑制剂，EDTA和EGTA，也进行了测试，并没有观察到28 kDa的细胞外肽酶的活性的变化。同样，E-64（一种半胱氨酸肽酶抑制剂）、苯甲基磺酰氟（一种丝氨酸肽酶抑制剂）和胃酶抑素A（一种乙酰基肽酶抑制剂）也没有显著改变酶的行为。总的来说，我们第一次描述了在人类机会致病真菌鲍氏毕赤酵母的细胞外金属肽酶的表达。
Pseudallescheria boydii is a ubiquitous filamentous fungus capable of causing invasive disease in humans. In the present study, using sodium dodecyl sulfate-polyacrylamide gels containing bovine serum albumin as co-polymerized substrate, we identified a 28-kDa proteolytic activity released to the extracellular environment by mycelia of P. boydii. This peptidase was detected during the growth of P. boydii in Sabouraud-dextrose medium for 13 days and reached its maximal production on day 7. The 28-kDa peptidase was active in acidic pH (5.5) and had its activity completely blocked by 1,10-phenanthroline, a potent zinc-metallopeptidase inhibitor. Two other metallopeptidase inhibitors, EDTA and EGTA, were also tested and no alterations were observed in the activity of the 28-kDa extracellular peptidase. Likewise, E-64 (a cysteine peptidase inhibitor), phenylmethylsulphonyl fluoride (a serine peptidase inhibitor), and pepstatin A (an aspartyl peptidase inhibitor) did not significantly alter the enzymatic behavior. Collectively, we described for the first time the expression of an extracellular metallopeptidase in the human opportunistic fungal pathogen P. boydii.