Rhodes W G, Lindberg R A, Drucker H
Arch Biochem Biophys. 1983 Jun;223(2):514-20. doi: 10.1016/0003-9861(83)90616-1.
An extracellular acid protease was purified 1420-fold from sulfur-starved protein-induced cultures of Neurospora crassa. The enzyme was homogeneous as determined by polyacrylamide electrophoresis. The purification procedure consisted of an ultrafiltration step, cation-exchange chromatography, and affinity chromatography on Sepharose-linked pepstatin. The enzyme is homologous to aspartyl proteases that are characterized by pepstatin inhibition and trypsinogen activation. It is extremely autolytic, especially under denaturing conditions. The protease is stable between pH 3 and 7, showing optimal activity near pH 4.0 for both trypsinogen activation and hydrolysis of bovine serum albumin. The molecular weight of the enzyme was 34,500 by gel electrophoresis and gel filtration, and 34,975 by amino acid analysis.
从硫饥饿蛋白诱导的粗糙脉孢菌培养物中纯化出一种细胞外酸性蛋白酶，纯化倍数达1420倍。通过聚丙烯酰胺电泳测定，该酶为均一的。纯化步骤包括超滤、阳离子交换色谱以及在琼脂糖连接的胃蛋白酶抑制剂上进行亲和色谱。该酶与天冬氨酸蛋白酶同源，其特征在于受胃蛋白酶抑制剂抑制并激活胰蛋白酶原。它极易自溶，尤其是在变性条件下。该蛋白酶在pH 3至7之间稳定，在pH 4.0左右对胰蛋白酶原激活和牛血清白蛋白水解均表现出最佳活性。通过凝胶电泳和凝胶过滤测定，该酶的分子量为34,500，通过氨基酸分析测定为34,975。
