Marchlewicz B A, Duncan J L
Infect Immun. 1981 Dec;34(3):787-94. doi: 10.1128/iai.34.3.787-794.1981.
An improved procedure for the isolation and purification of the hemolysin produced by a group B streptococcus was developed, and the inactivation of partially purified hemolysin by several enzymes was studied. Hemolysin obtained in buffer containing starch and Tween 80 was inactivated by subtilisin and alpha-amylase, suggesting that the hemolysin may consist of a protein hemolytic moiety complexed to starch which acts as a carrier or stabilizer. Properties of the hemolytic reaction were studied by using sheep erythrocytes as target cells. Experiments to examine the kinetics of hemolysis at different hemolysin concentrations resulted in a family of sigmoidal curves characterized by a short prelytic lag phase followed by a period of rapid release of hemoglobin. The binding of the group B hemolysin at 37 degrees C was rapid; within 3 min, most of the cells had bound sufficient hemolysin to produce lysis. In contrast, the hemolysin did not bind to erythrocytes at 0 degrees C. The length of the prelytic lag period and the rate of hemolysis were also temperature dependent. A decrease in total hemolysis was observed when the target cell/hemolysin ratio was increased, suggesting that a multihit response is required for lysis. Intracellular 86Rb and hemoglobin were released at the same rate from hemolysin-treated cells, indicating that a colloid-osmotic process is not involved in the lytic mechanism.
开发了一种改进的程序，用于分离和纯化B组链球菌产生的溶血素，并研究了几种酶对部分纯化的溶血素的灭活作用。在含有淀粉和吐温80的缓冲液中获得的溶血素被枯草杆菌蛋白酶和α-淀粉酶灭活，这表明溶血素可能由与淀粉复合的蛋白质溶血部分组成，淀粉充当载体或稳定剂。以绵羊红细胞为靶细胞研究了溶血反应的特性。在不同溶血素浓度下检测溶血动力学的实验产生了一系列S形曲线，其特征是溶血前的延迟期较短，随后是血红蛋白快速释放的时期。B组溶血素在37℃时的结合很快；在3分钟内，大多数细胞已结合了足够的溶血素来产生裂解。相比之下，溶血素在0℃时不与红细胞结合。溶血前延迟期的长度和溶血速率也与温度有关。当靶细胞/溶血素比率增加时，观察到总溶血减少，这表明裂解需要多次打击反应。溶血素处理的细胞中细胞内86Rb和血红蛋白以相同的速率释放，这表明胶体渗透过程不参与裂解机制。
