Monod M, Togni G, Rahalison L, Frenk E
Service de Dermatologie, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
J Med Microbiol. 1991 Jul;35(1):23-8. doi: 10.1099/00222615-35-1-23.
Aspergillus fumigatus secreted an inducible alkaline protease (AlPase) when cultivated in the presence of collagen (200 micrograms/ml) as sole nitrogen and carbon source. Proteolytic activity was maximum at pH 9.0 with azocollagen as substrate. The enzyme, which was the major protein found in the supernate of a liquid culture, was purified by ammonium sulphate precipitation and gel filtration. The Mr was determined to be 33 Kda by gel filtration and sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The isoelectric point was estimated to be pH 8.2. Divalent cations strongly inhibited enzyme activity, whereas non-ionic detergents and reducing agents had no effect. A. fumigatus AlPase was totally inhibited by phenylmethanesulphonyl fluoride, antipain, chymostatin and alpha-2-macroglobulin. A. fumigatus AlPase is closely related to the A. oryzae AlPase, a serine protease of the subtilisin family, as attested by the antigen pattern seen by immunoblotting. The high collagenic activity and the ability of A. fumigatus AlPase to digest elastin could play a role in the invasion of the tissues by the fungus.
烟曲霉在以胶原蛋白（200微克/毫升）作为唯一氮源和碳源进行培养时，会分泌一种诱导型碱性蛋白酶（AlPase）。以偶氮胶原蛋白为底物时，蛋白水解活性在pH 9.0时达到最大值。该酶是液体培养上清液中发现的主要蛋白质，通过硫酸铵沉淀和凝胶过滤进行纯化。通过凝胶过滤和十二烷基硫酸钠-聚丙烯酰胺凝胶电泳测定其分子量为33 kDa。估计其等电点为pH 8.2。二价阳离子强烈抑制酶活性，而非离子洗涤剂和还原剂则无影响。烟曲霉AlPase完全被苯甲基磺酰氟、抗蛋白酶、抑肽酶和α-2-巨球蛋白抑制。免疫印迹所见的抗原模式证明，烟曲霉AlPase与米曲霉AlPase密切相关，米曲霉AlPase是枯草杆菌蛋白酶家族的一种丝氨酸蛋白酶。烟曲霉AlPase的高胶原蛋白活性和消化弹性蛋白的能力可能在真菌对组织的侵袭中起作用。
