VIRAL MEMBRANE AND GLYCOPROTEIN STRUCTURE

描述：（逐字摘自申请人的摘要）新出现的感染： 研究流感病毒株具有传染性的机制 对于人类，我们计划检查 X 射线结构和功能 来自病毒株的血凝素显然仅限于感染动物 储存库并用于比较主要的人类感染菌株 流行病。细胞受体上不同唾液酸苷键的偏好 与动物与人类的感染传播相关。目标之一是 帮助解释观察结果，例如为什么过去两年在香港爆发疫情 人类感染的禽流感病毒并未传播到人群中。 病毒进入机制：为了研究流感病毒的膜融合，我们 计划完整HA的蛋白质/洗涤剂复合物的晶体结构研究 HA2 以及 HA 与膜相互作用的机制研究 聚变反应的中间体。假设HA2在低pH值下 通过晶体学观察到的构象是膜融合活性的也将是 用转染在适合的细胞中的完整重组HA2分子进行测试 膜融合测定。假设 N 端和 C 端片段 HA1加上所有HA2（BHA的茎）是祖先膜融合蛋白 通过设计这样的蛋白质来测试它是否可以 低 pH 值下的蛋白水解引发和激活，以及 HA1 片段是否 具有一定的作用，例如在包含假定的多三聚体的组装中 毛孔。 M2 离子通道：生成有关离子通道的结构信息 流感病毒的蛋白 M2 我们建议在洗涤剂中结晶 我们生产的细菌表达和重折叠的 M2 四聚体；和/或一个 通道活性合成跨膜螺旋的四聚体。复合物与 抑制药物金刚烷胺也将被研究。

Description: (Verbatim from the applicant's abstract) Emerging Infections: To study the mechanism by which influenza virus strains can emerge as infectious to humans, we plan to examine the X-ray structure and function of hemagglutinins from viral strains apparently limited to infecting animal reservoirs and for comparison human infectious strains from the major pandemics. Preferences for different sialoside linkages on cellular receptors correlate with the spread of infection in animals versus humans. One goal is to help explain observations like why outbreaks in the past two years in Hong Kong of avian virus infections in humans did not spread into the human population. Viral Entry Mechanisms: To investigate membrane fusion by influenza virus, we plan crystal structure studies of protein/detergent complexes of intact HA and HA2 and mechanistic studies of the interaction of HA with membranes and of intermediates in the fusion reaction. The hypothesis that HA2 in the low pH conformation observed by crystallography is membrane fusion active will also be tested with intact recombinant HA2 molecules transfected in cells suitable for membrane fusion assays. The hypothesis that the N- and C-terminal segments of HA1 plus all of HA2 (BHA's stem) was an ancestral membrane fusion protein will be tested by engineering such a protein, testing whether it can be proteolytically primed and activated by low pH, and whether the HA1 segments have a role, such as in the assembly of a putative multi-trimer containing pore. M2 Ion Channel: To generate structural information about the ion channel protein M2 of influenza virus we propose crystallization in detergent of bacterially expressed and refolded M2 tetramers that we have produced; and/or a tetramer of a channel-active synthetic transmembrane helix. Complexes with the inhibitory drug, amantadine, will also be studied.