TOXINS OF PERTUSSIS--ISOLATION, CHARACTERIZATION AND MECHANISMS OF ACTION

百日咳毒素——分离、表征和作用机制

• 批准号: 4693832
• 负责人: R D SEKURA
• 金额: --
• 依托单位: EUNICE KENNEDY SHRIVER NATIONAL INSTITUTE OF CHILD HEALTH & HUMAN DEVELOPMENT
• 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/4693832
• 关键词: Bordetella pertussis; adenosine diphosphate; adenylate cyclase; bacterial toxicology; bacterial toxins; bactericidal immunity; catalyst; guanosine triphosphate; immunological substance; pertussis; pertussis vaccine; riboside; tissue /cell culture

Bordetella pertussis, microorganism which causes the disease commonly known as whooping cough, produces several toxins (i.e., pertussis toxin (PT) and heat labile or dermonecrotic toxin) (see project Z01 HD 01306 01) which appear to play important roles in pathogenesis of the organism. PT, in addition, is a major protective antigen which is a promising candidate for the development of a new acellular pertussis vaccine. The current project concentrates on elucidating the mechanisms by which pertussis toxin interacts with cells and elicits its diverse pharmacologic actions. The initial event in the interaction of PT with cells appears to be a rapid and essentially irreversible binding of toxin to cells. Using the interaction of PT with fetuin as a model, studies have been conducted which demonstrate that PT interacts with the carbohydrate moieties pressent in fetuin. The structure of the carbohydrate responsible for interaction with PT has been characterized and binding constants have been determined. The toxic action of PT is mediated by toxin catalyzed transfer of the ADP-ribose moiety from NAD to the adenylate cyclase regulatory component, Ni. This action of PT has been used as a probe to explore the role of Ni in regulation of cell function, and the changes of the regulatory component in response to desensitization. These studies have shown that PT catalyzed modification of Mi reduces receptor affinity and abolishes the action of GTP in producing the high affinity binding state without blocking the capacity of nonhydrolizable GTP analogs to mediate cyclase activation. Use of PT as a probe to examine Ni following glucogen desensitization of MDCK cells showed increased availability of Ni for ADP-ribosylation. This leads to the suggestion that hormone induced desensitization results from increased Ni or mobilization of Ni to pools that affect receptor mediated regulation of adenylate cyclase.

百日咳博德特氏菌，引起疾病的微生物， 如百日咳，产生几种毒素（即，百日咳毒素（PT）和 热不稳定或皮肤坏死毒素）（见项目Z 01 HD 01306 01）， 似乎在机体的发病机制中起重要作用。 PT列出的 此外，是一种主要的保护性抗原，是一种有希望的候选抗原， 新型无细胞百日咳疫苗的研制。 当前项目 致力于阐明百日咳毒素 与细胞相互作用并激发其多种药理作用。 的 PT与细胞相互作用的初始事件似乎是快速的， 毒素与细胞基本上不可逆的结合。 使用交互 以胎球蛋白为模型的PT，已经进行了研究，证明 PT与胎球蛋白中的碳水化合物相互作用。 的 负责与PT相互作用的碳水化合物的结构已经被 的特征和结合常数已被确定。 毒性作用 的PT是由毒素催化的ADP-核糖部分从 NAD与腺苷酸环化酶调节组分Ni。 PT的这一行动 作为一种探针，探讨了镍在细胞凋亡调控中的作用。 功能，以及响应于 脱敏 这些研究表明，PT催化改性 Mi的降低受体亲和力并消除GTP在 产生高亲和力结合状态而不阻断 不可水解的GTP类似物介导环化酶活化。 使用PT作为 检测MDCK细胞糖原脱敏后Ni的探针显示， 增加了用于ADP-核糖基化的Ni的可用性。 这导致 提示激素诱导脱敏是由于镍含量增加所致 或动员镍池，影响受体介导的调节， 腺苷酸环化酶