STUDIES OF THE STRUCTURE AND FUNCTION OF PERTUSSIS TOXIN

百日咳毒素的结构和功能研究

• 批准号: 2568888
• 负责人: D L BURNS
• 金额: --
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/2568888
• 关键词: Bordetella pertussis; Brucellaceae; bacterial genetics; bacterial proteins; gene expression; genetic promoter element; genetic strain; operon; pertussis toxin; protein biosynthesis; protein structure function; species difference

Research was conducted to investigate the biosynthesis of pertussis toxin (PT) as well as the structure/function relationships of the toxins. While the current dogma in the field is that only B. pertussis produces PT, recent clinical trials have provided provocative results which may suggest otherwise. A number of clinical investigators have reported that sera from children infected with either B. parapertussis or B. bronchiseptica can show antibody rises to PT. It has been known for some time that both B. parapertussis and B. bronchispetica contain ptx genes but the genes were thought to be transcriptionally silent. We asked the question of whether the ptx genes of B. parapertussis and B. bronchiseptica could produce functionally active PT, if the genes were expressed. We constructed strains of both B. parapertussis and B. bronchiseptica which had the B. pertussis ptx promoter inserted immediately in front of the ptx-ptl regions of those strains. We found that both species produced active PT as well as at least certain of the Ptl proteins. The S2 subunit was confirmed to be prematurely terminated in B. parapertussis. Nonetheless, an active toxin was produced, although this toxin appeared to be more labile than PT. These results suggest that, if the ptx-ptl genes of B. parapertussis and B. bronchiseptica were expressed during the disease process, they would be functionally active and might contribute to pathogenesis. We are currently using genetic and molecular biological techniques to determine whether the ptx genes of B. parapertussis and B. bronchiseptica are ever expressed in vitro or during the course of infection in vivo.

研究了百日咳毒素的生物合成 (PT)以及毒素的结构/功能关系。 而目前该领域的教条是，只有B。百日咳产生 PT，最近的临床试验提供了挑衅性的结果， 不是这么说的 一些临床研究者报告说， 感染B的儿童血清。副百日咳或B. B. 支气管败血症可表现为PT抗体升高。 它已经被称为一些 两个B的时间。副百日咳和B.支气管炎包含ptx基因 但这些基因被认为是转录沉默的。 我们要求 B.副百日咳和B. 支气管败血症可以产生功能活性PT，如果基因 表达。 我们构建了两种B的菌株。副百日咳和B. 支气管败血症，其中有B。插入百日咳ptx启动子 紧邻这些菌株的PTX-PTL区域的前面。 我们发现 这两个物种都产生了活性PT， Ptl蛋白。 证实S2亚基提前终止 在B。副百日咳。 尽管如此，还是产生了一种活性毒素， 这种毒素似乎比PT更不稳定。 这些结果表明 如果B.副百日咳和B.支气管败血症是 在疾病过程中表达， 并可能导致发病。 我们目前正在使用基因和 分子生物学技术检测B. 副百日咳和B.支气管败血症的表达， 体内感染的过程。