Tsuboi R, Sanada T, Ogawa H
Department of Dermatology, Juntendo University School of Medicine, Tokyo, Japan.
J Clin Microbiol. 1988 Jul;26(7):1431-3. doi: 10.1128/jcm.26.7.1431-1433.1988.
Sporothrix schenckii produces two extracellular proteinases in albumin- or collagen-supplemented unbuffered liquid medium. Proteinase I had an optimal pH of 6.0, and its activity was strongly inhibited by chymostatin. Proteinase II had an optimal pH of 3.5, and its activity was strongly inhibited by pepstatin. Speculating that these two proteinases are key enzymes for fungal growth, we investigated the influences of culture medium pH and either or both of the proteinase inhibitors pepstatin and chymostatin on the cell growth of S. schenckii. In buffered medium at a pH of 3.5, an optimal pH for proteinase II, only proteinase II activities were observed, while at pH 6.0, an optimal pH for proteinase I, only proteinase I activities were observed. However, there was no cell growth inhibition. These results suggested that the regulation of the production of the two proteinases is dependent on environmental pH. The addition of pepstatin or chymostatin to the culture medium did not inhibit the cell growth of S. schenckii, but the addition of both inhibitors at a concentration of 10 micrograms/ml strongly inhibited growth. These results suggested that at least one of the two proteinases was expressed to allow fungal growth in albumin-supplemented media. The indirect fungistatic action of the proteinase inhibitors, which inhibit proteolysis, may be applied to a topical therapeutic agent in vivo.
申克孢子丝菌在添加白蛋白或胶原蛋白的无缓冲液体培养基中产生两种细胞外蛋白酶。蛋白酶I的最适pH为6.0，其活性受到抑肽酶的强烈抑制。蛋白酶II的最适pH为3.5，其活性受到胃蛋白酶抑制剂的强烈抑制。推测这两种蛋白酶是真菌生长的关键酶，我们研究了培养基pH以及蛋白酶抑制剂胃蛋白酶抑制剂和抑肽酶中的一种或两种对申克孢子丝菌细胞生长的影响。在pH为3.5（蛋白酶II的最适pH）的缓冲培养基中，仅观察到蛋白酶II的活性，而在pH 6.0（蛋白酶I的最适pH）时，仅观察到蛋白酶I的活性。然而，没有细胞生长抑制现象。这些结果表明，两种蛋白酶产生的调节取决于环境pH。向培养基中添加胃蛋白酶抑制剂或抑肽酶不会抑制申克孢子丝菌的细胞生长，但以10微克/毫升的浓度添加两种抑制剂会强烈抑制生长。这些结果表明，两种蛋白酶中至少有一种表达以允许真菌在添加白蛋白的培养基中生长。抑制蛋白水解的蛋白酶抑制剂的间接抑菌作用可应用于体内局部治疗剂。
