STRUCTURE DETERMINATION OF PERTUSSIS TOXIN

建议确定百日咳的三维结构 毒素的高分辨率X射线晶体学。 Pt是一种蛋白质外毒素 由百日咳博德特氏菌产生， 一种被称为百日咳的疾病， 婴儿死亡，每年全球死亡人数超过100万。 一 本研究的具体目标是确定这些结构特征 PT，这是重要的，在引发保护性免疫反应后， 自然感染或接种疫苗。虽然保护性疫苗从 未分馏的B。百日咳细胞长期以来一直可用，它们通常 与不良副作用相关，包括罕见的神经系统疾病 损伤 改进疫苗的开发，没有有害的 复杂性，需要最小分子结构的定义 保护性反应被调动起来。 因为百日咳毒素 被认为是疾病的主要毒力因子，特异性免疫 对PT的反应几乎肯定是保护所必需的。 高 铂的分辨率结构与现有的遗传和 生物化学数据将允许识别涉及的结构特征， 免疫原性，使得能够区分这些区域 这种分子可以对那些仅仅引发 回应. ping 另一个重要原因是获得更详细的 关于PT的结构信息是，其作用方式是 干扰基本信号的关键分量 真核细胞的转导机制。 当前统一 一种假说是，在细胞膜上有多种受体介导的事件， 细胞膜受到一类称为G蛋白的蛋白质的影响。 它 已知Pt催化G蛋白的共价修饰， 从NAD+转移ADP-核糖。 最后，工作的一个重要目的是 是更好地理解机制中涉及的基本原理， 其中蛋白质如PT的A亚基被细胞内化， 在与易位复合物如B亚基相互作用后， 的PT。 PT的三维结构可以更有效地 最安全的百日咳疫苗，为设计 偶联至癌细胞靶向抗体的细胞毒性剂，和 有助于我们更好地理解基础受体生物学， 肿瘤发生

It is proposed to determine the three-dimensional structure of pertussis toxin by high resolution x-ray crystallography. Pt is a protein exotoxin produced by Bordetella pertussis, the bacterium that causes the infectious disease known as whooping cough, a disease affecting over 60 million infants and leading to over one million deaths per year world-wide. A specific objective of this research is to define those structural features of PT that are important in eliciting the protective immune response after natural infection or vaccination. Although protective vaccines prepared rom unfractionated B. pertussis cells have long been available, they are often associated with adverse side effects including rare cases of neurological impairment. The development of improved vaccines, free of deleterious complications, requires the definition of the minimal molecular structures against which the protective response is mobilized. Since pertussis toxin is considered a major virulence factor in the disease, the specific immune response to PT is almost certainly essential for protection. A high resolution structure of Pt in conjunction with available genetic and biochemical data would allow recognition of structural features involved in the immunogenicity, enabling a distinction to be made between those regions of the molecule conferring protective immunity from those simply eliciting a response. Another important reason for obtaining more detailed structural information concerning PT is that its mode of action is the interference with a critical component of the fundamental signal transduction machinery of eukaryotic cells. The current unifying hypothesis is that a wide variety of receptor mediated events at the membranes are effected by a class of proteins known as the G proteins. It is known that Pt catalyses the covalent modification of G proteins by transferring ADP-ribose from NAD+. Finally, an important aim of the work is to better understand the basic principles involved in mechanisms by which proteins such as the A subunit of PT are internalized by cells at the membrane after interaction with translocating complexes like the B subunit of PT. A three-dimensional structure of PT could lead to more effective and safest vaccines against whooping cough, provide a basis for designing cytotoxic agents coupled to cancer cells targeting antibodies, and contribute to our improved understanding of basic receptor biology and oncogenesis.