Department of Microbiology and Department of Genetics, University of Groningen, Kerklaan 30, 9751 NN Haren, The Netherlands.
Appl Environ Microbiol. 1987 Apr;53(4):853-9. doi: 10.1128/aem.53.4.853-859.1987.
Two components of the proteolytic system, proteins A and B (J. Hugenholtz, F. Exterkate, and W. N. Konings, Appl. Environ. Microbiol. 48:1105-1110, 1984), have been studied in Streptococcus cremoris Wg2 by immunological methods. The components could not be separated by standard chromatography techniques because both proteins had almost identical molecular weights (about 140,000) and isoelectric points (pH 4.5). Specific antibodies were raised against proteins A and B by excision of the different immunoprecipitates from crossed immunoelectrophoresis gels. With these antibodies, protein A or B was removed from solutions containing both proteins. The purified proteins A and B possessed proteolytic activity and were inhibited by the serine protease inhibitor phenylmethylsulfonyl fluoride. Each of these proteins accounted for approximately 50% of the total proteolytic activity isolated from S. cremoris Wg2. The specific antibodies against the proteases were also used for immuno-gold labeling studies. The proteases were clearly seen to be located at the outside of the cell wall. The proteases had the same location when the genetic information coding for the proteases was cloned in Streptococcus lactis and Bacillus subtilis.
两种蛋白水解系统成分，蛋白 A 和蛋白 B（J. Hugenholtz，F. Exterkate 和 W. N. Konings，应用环境微生物学 48：1105-1110，1984 年），已经通过免疫学方法在乳链球菌 Wg2 中进行了研究。由于这两种蛋白质的分子量（约 140000）和等电点（pH4.5）几乎相同，因此无法通过标准色谱技术将它们分离。通过从交叉免疫电泳凝胶中切出不同的免疫沉淀，针对蛋白 A 和蛋白 B 产生了特异性抗体。使用这些抗体，可以从含有两种蛋白质的溶液中去除蛋白 A 或蛋白 B。纯化的蛋白 A 和 B 具有蛋白水解活性，并被丝氨酸蛋白酶抑制剂苯甲基磺酰氟抑制。从乳链球菌 Wg2 中分离的总蛋白水解活性中，这两种蛋白质各占约 50%。针对蛋白酶的特异性抗体也用于免疫金标记研究。当蛋白酶的遗传信息在乳链球菌和枯草芽孢杆菌中被克隆时，可以清楚地看到蛋白酶位于细胞壁的外部。
