Intermedilysin, a novel cytotoxin specific for human cells, secreted by Streptococcus intermedius UNS46 isolated from a human liver abscess
Intermedilysin, a novel cytotoxin specific for human cells, secreted by Streptococcus intermedius UNS46 isolated from a human liver abscess
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DOI：
10.1128/iai.64.8.3093-3100.1996
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发表时间：
1996-08-01
影响因子：
3.1
通讯作者：
Matsuda, Y
中科院分区：
文献类型：
--
作者：
Nagamune, H;Ohnishi, C;Matsuda, Y
从人肝脓肿分离的中间链球菌UNS 46中分离到一种新的细胞毒素（中间溶素），它是一种细胞溶解因子。中间溶素导致人类细胞死亡，并产生膜泡。通过凝胶过滤和疏水层析从UNS 46培养基中纯化中间溶素。通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳，将纯化的毒素分别解析为54和53 kDa的主要和次要条带。这些蛋白质与抗中间溶素的抗体反应。五个内部肽片段的intermedilysin进行测序，发现有42至71%的同源性与硫醇活化的细胞毒素肺炎球菌溶血素。然而，中间溶素的作用不同于硫醇活化的细胞毒素，特别是在缺乏二硫苏糖醇的活化和对处理的抗性方面，vith N-乙基马来酰亚胺和5，5 '-二硫-双-（2-硝基苯甲酸），尽管胆固醇抑制毒素活性。中间溶素对人红细胞具有强效溶血性，但对黑猩猩和食蟹猴红细胞的有效性低100倍。中间溶素在其他9种受试动物种属中不具有溶血性。由于用胰蛋白酶处理的人红细胞对中间溶素的敏感性远低于完整细胞，因此细胞膜蛋白可能参与中间溶素的作用。这些数据表明，中间溶素与所有已知的细菌溶细胞素是可区分的。
A novel cytotoxin (intermedilysin) specific for human cells was identified as a cytolytic factor of Streptococcus intermedius UNS46 isolated from a human liver abscess. Intermedilysin caused human cell death with membrane blebs. Intermedilysin was purified from UNS46 culture medium by means of gel filtration and hydrophobic chromatography. The purified toxin was resolved into major and minor bands of 54 and 53 kDa, respectively, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These proteins reacted with an antibody against intermedilysin. Five internal peptide fragments of intermedilysin were sequenced and found to have 42 to 71% homology with the thiol-activated cytotoxin pneumolysin. However, the action of intermedilysin differed from that of thiol-activated cytotoxins, especially in terms of a lack of activation by dithiothreitol and resistance to treatments,vith N-ethylmaleimide and 5,5'-dithio-bis-(2-nitrobenzoic acid), although cholesterol inhibited the toxin activity. Intermedilysin was potently hemolytic on human erythrocytes but was 100-fold less effective on chimpanzee and cynomolgus monkey erythrocytes. Intermedilysin was not hemolytic in nine other animal species tested. Since human erythrocytes treated with trypsin were far less sensitive to intermedilysin than were the intact cells, a cell membrane protein(s) may participate in the intermedilysin action. These data demonstrated that intermedilysin is distinguishable from all known bacterial cytolysins.