Hausdorf G, Krüger K, Höhne W E
Int J Pept Protein Res. 1980 May;15(5):420-9. doi: 10.1111/j.1399-3011.1980.tb02917.x.
Studies on the amino acid composition, chemical modifications, and characterization of the cyanogen bromide cleavage peptides of a thermostable serine protase (thermitase) from Thermoactinomyces vulgaris were performed. The amino acid analysis shows that the enzyme contains a single cysteine and methionine residue. From the amino acid composition as well as a partial sequence determination around the single methionine residue it is concluded that thermitase belongs to the subtilisin-type proteases. The two peptides obtained by cyanogen bromide cleavage were further characterized by amino acid analysis and molecular weight determination yielding 25 000 and 6 000 daltons, respectively. Chemical modification experiments show that in addition to the active site serine and histidine residue the cysteine as well as the methionine residue are essential for activity of the enzyme. The alignment of these amino acids in the polypeptide chain of the thermitase is supposed.
对来自普通嗜热放线菌的一种耐热丝氨酸蛋白酶（嗜热菌蛋白酶）的氨基酸组成、化学修饰及溴化氰裂解肽段进行了研究。氨基酸分析表明该酶含有一个半胱氨酸和一个甲硫氨酸残基。从氨基酸组成以及围绕单个甲硫氨酸残基的部分序列测定结果可得出结论，嗜热菌蛋白酶属于枯草杆菌蛋白酶类型的蛋白酶。通过溴化氰裂解得到的两个肽段，进一步通过氨基酸分析和分子量测定进行表征，分子量分别为25000道尔顿和6000道尔顿。化学修饰实验表明，除了活性位点的丝氨酸和组氨酸残基外，半胱氨酸和甲硫氨酸残基对该酶的活性也至关重要。推测了这些氨基酸在嗜热菌蛋白酶多肽链中的排列方式。
