Yoo Ji Jae il, Lee Yeong Seon, Song Chul-Yong, Kim Bong Su
Laboratory of Antimicrobial Resistant Pathogens, Department of Bacteriology, National Institute of Health, Chung-Ang University, Seoul, Korea.
J Clin Microbiol. 2004 Feb;42(2):722-6. doi: 10.1128/JCM.42.2.722-726.2004.
An extracellular proteinase was purified from culture filtrates of Cryptococcus neoformans NHPY24 by DEAE ion-exchange chromatography and gelatin affinity column chromatography with azoalbumin as the substrate. The molecular mass of the purified enzyme was 43 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, its pH optimum was 7.0 to 8.0, and maximal activity was obtained at pH 7.5 and 37 degrees C. By isoelectric focusing, the purified enzyme had a pI of 4.77. Enzyme activity was inhibited by serine proteinase inhibitors such as phenylmethylsulfonyl fluoride and diisopropylfluorophosphate. The purified enzyme was thus a serine proteinase. It hydrolyzed natural substrates including hemoglobin, beta-casein, and gamma globulin.
以偶氮白蛋白为底物，通过DEAE离子交换色谱和明胶亲和柱色谱，从新型隐球菌NHPY24的培养滤液中纯化出一种细胞外蛋白酶。经十二烷基硫酸钠-聚丙烯酰胺凝胶电泳测定，纯化酶的分子量为43 kDa，其最适pH为7.0至8.0，在pH 7.5和37℃时活性最高。通过等电聚焦，纯化酶的pI为4.77。丝氨酸蛋白酶抑制剂如苯甲基磺酰氟和二异丙基氟磷酸可抑制酶活性。因此，纯化酶为丝氨酸蛋白酶。它能水解包括血红蛋白、β-酪蛋白和γ球蛋白在内的天然底物。
