THE CYTOLYTIC TOXIN AEROLYSIN MUST AGGREGATE TO DISRUPT ERYTHROCYTES, AND AGGREGATION IS STIMULATED BY HUMAN GLYCOPHORIN
THE CYTOLYTIC TOXIN AEROLYSIN MUST AGGREGATE TO DISRUPT ERYTHROCYTES, AND AGGREGATION IS STIMULATED BY HUMAN GLYCOPHORIN
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DOI：
10.1128/iai.56.5.1249-1253.1988
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发表时间：
1988-05-01
影响因子：
3.1
通讯作者：
BUCKLEY, JT
中科院分区：
文献类型：
--
作者：
GARLAND, WJ;BUCKLEY, JT
空洞形成毒素溶血素在37℃与红细胞结合后聚集。虽然蛋白质也在4℃结合和聚集，但没有观察到空穴形成，表明聚集先于脂质双层渗透。用组氨酸反应性试剂焦碳酸二乙酯对毒素进行预处理，可以阻止聚集，但不能阻止结合。这导致了毒素的失活。从人红细胞中提纯的血糖素与溶气素孵育可引起聚集和完全失活。缺乏血糖素的红细胞对这种毒素不太敏感。溶气素原是溶气素的非活性前体，也与红细胞结合；然而，它既不聚集，也不与血糖素预先孵育时聚集。原毒素即使在与红细胞结合后，也可以通过胰酶处理而被激活。激活也可以通过前溶气素与各种其他酶的反应来实现，每种酶都会带来类似的蛋白质相对分子质量的降低。活化后的蛋白对进一步的蛋白降解具有抵抗力。这些结果表明，聚集是形成空穴的必要步骤，溶气素上结合所需的位置以及聚集和空穴形成所需的位置是分开的。
The hole-forming toxin aerolysin was shown to aggregate after binding to erythrocytes at 37.degree.C. Although the protein also bound and aggregated at 4.degree.C, hole formation was not observed, indicating that aggregation preceded penetration of the lipid bilayer. Aggregation, but not binding, could be blocked by pretreatment of the toxin with diethyl pyrocarbonate, a histidine-reactive reagent. This resulted in inactivation of the toxin. Incubation of aerolysin with glycophorin purified from human erythrocytes caused aggregation and complete inactivation. Erythrocytes which lacked glycophorin were less sensitive to the toxin. Proaerolysin, the inactive precursor of aerolysin, also bound to erythrocytes; however, it did not aggregate, nor did it aggregate when preincubated with glycophorin. The protoxin could be activated by treatment with trypsin even after it had bound to erythrocytes. Activation could also be achieved by reaction of proaerolysin with a variety of other proteases, each of which brought about a similar reduction in protein molecular weight. The activated protein was resistant to further proteolysis. These results indicate that aggregation is a necessary step in hole formation and that the sites on aerolysin required for binding and for aggregation and hole formation are separate.