Shoer R, Rappaport H P
J Bacteriol. 1972 Feb;109(2):575-83. doi: 10.1128/jb.109.2.575-583.1972.
A Bacillus subtilis mutant having a phenotype manifesting reduced extracellular proteolytic activity was investigated. An extracellular protein was isolated and shown by fingerprint analysis to be a fragment of the wild-type enzyme. By using previously established molecular weights for the wild-type enzyme (2.9 x 10(4)) and the two polypeptide chains derived from it (1.4 x 10(4) each), with the amino acid analysis and fingerprints of both wild-type and mutant proteins, a molecular weight of 1.57 x 10(4) was assigned to the mutant protein. (32)P-diisopropylphosphate labeling of the mutant protein showed only 1 in 53 molecules to be functional. Thin-layer chromatography on Sephadex G-75 demonstrated that the active molecules were separable from the bulk of the isolated protein and had the same mobility as the wild-type enzyme. Fingerprints of tryptic digests of (32)P-diisopropylphosphate-labeled wild-type and mutant proteins showed that the labeled peptides had identical characteristics.
对一株具有细胞外蛋白水解活性降低表型的枯草芽孢杆菌突变体进行了研究。分离出一种细胞外蛋白，经指纹分析表明它是野生型酶的一个片段。利用先前确定的野生型酶的分子量（2.9×10⁴）及其衍生的两条多肽链的分子量（每条1.4×10⁴），结合野生型和突变型蛋白的氨基酸分析及指纹图谱，确定突变型蛋白的分子量为1.57×10⁴。用（³²）P - 二异丙基磷酸对突变型蛋白进行标记，结果显示53个分子中只有1个具有活性。在Sephadex G - 75上进行的薄层色谱分析表明，活性分子与大部分分离出的蛋白可分离，并与野生型酶具有相同的迁移率。（³²）P - 二异丙基磷酸标记的野生型和突变型蛋白的胰蛋白酶消化产物的指纹图谱显示，标记的肽具有相同的特征。
