• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Infection and immunity >Clostridium sordellii Lethal Toxin Is Maintained in a Multimeric Protein Complex
【24h】

Clostridium sordellii Lethal Toxin Is Maintained in a Multimeric Protein Complex

机译：梭状芽胞杆菌致死毒素被维持在多聚体蛋白质复合物中。

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Clostridium sordellii lethal toxin (TcsL) is distinct among large clostridial toxins (LCTs), as it is markedly reduced in its rate of intoxication at pH 8.0 yet is cytotoxic at pH 4.0. Results from the present study suggest that TcsL's slow rate of intoxication at pH 8.0 is linked to formation of a high-molecular-weight complex containing dissociable pH 4.0-sensitive polypeptides. The cytosolic delivery of TcsL's enzymatic domain by using a surrogate cell entry system resulted in cytopathic effect rates similar to those of other LCTs at pH 8.0, further indicating that rate-limiting steps occurred at the point of cell entry. Since these rate-limiting steps could be overcome at pH 4.0, TcsL was examined across a range of pH values and was found to dissociate into distinct 45- to 55-kDa polypeptides between pH 4.0 and pH 5.0. The polypeptides reassociated when shifted back to pH 8.0. At pH 8.0, this complex was resistant to sodium dodecyl sulfate (SDS) and multiple proteases; however, following dissociation, the polypeptides became protease sensitive. Dissociation of TcsL, and cytotoxicity, could be blocked by preincubation with ethylene glycol bis(sulfosuccinimidylsuccinate), resulting in cross-linking of the polypeptides. TcsL was also examined at pH 8.0 by using SDS-agarose gel electrophoresis and transmission electron microscopy and was found to exist in a higher-molecular-weight complex which resolved at a size exceeding 750 kDa and also dissociated at pH 4.0. However, this complex did not reassemble following a shift back to pH 8.0. Collectively, these data suggest that TcsL is maintained in a protease-resistant, high-molecular-weight complex, which dissociates at pH 4.0, leading to cytotoxicity.
机译：梭状芽胞杆菌致死毒素（TcsL）在大型梭菌毒素（LCT）中是不同的，因为它在pH 8.0时的中毒率明显降低，而在pH 4.0时具有细胞毒性。来自本研究的结果表明，TcsL在pH 8.0下的缓慢中毒速率与含有可分离的pH 4.0敏感多肽的高分子量复合物的形成有关。通过使用替代细胞进入系统，TcsL的酶促结构域的胞质递送导致细胞病变效应速率与其他LCT在pH 8.0时相似，进一步表明速率限制步骤发生在细胞进入时。由于这些限速步骤可以在pH 4.0时克服，因此在一系列pH值范围内检查了TcsL，发现它在pH 4.0至pH 5.0时解离成45-55 kDa的不同多肽。当移回pH 8.0时，多肽重新结合。在pH 8.0时，该复合物对十二烷基硫酸钠（SDS）和多种蛋白酶具有抗性。然而，解离后，多肽变得对蛋白酶敏感。 TcsL的解离和细胞毒性可通过与乙二醇双（磺基琥珀酰亚胺基琥珀酸酯）预孵育来阻止，从而导致多肽的交联。还通过使用SDS-琼脂糖凝胶电泳和透射电子显微镜在pH 8.0下检测了TcsL，发现其存在于较高分子量的复合物中，该复合物以超过750 kDa的大小分解并且在pH 4.0下也解离。然而，该复合物在重新回到pH 8.0后并未重新组装。总的来说，这些数据表明TcsL被保持在耐蛋白酶的高分子量复合物中，该复合物在pH 4.0下解离，从而导致细胞毒性。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号