VIRAL MEMBRANE AND GLYCOPROTEIN STRUCTURE

描述：（逐字摘自申请人摘要）新发感染：至 研究流感病毒株出现传染性的机制 我们计划检查X射线的结构和功能， 来自病毒株的血凝素显然仅限于感染动物 水库和比较人类感染菌株从主要的 流行病对细胞受体上不同唾液酸糖苷键的偏好 与动物和人类的感染传播有关。一个目标是 有助解释观察所得的现象，例如为何香港过去两年爆发禽流感， 禽流感病毒在人类中的感染并没有传播到人类中。 病毒进入机制：为了研究流感病毒的膜融合，我们 完整HA的蛋白质/去污剂复合物的平面晶体结构研究， HA 2和HA与膜的相互作用的机理研究， 聚变反应中的中间体。假设HA 2在低pH下 晶体学观察到的构象是膜融合活性的， 用转染在适合于以下的细胞中的完整重组HA 2分子测试： 膜融合测定。假设N-和C-末端片段的 HA 1加上全部HA 2（BHA的茎）是一个祖先膜融合蛋白， 通过设计这样的蛋白质来测试，测试它是否可以 蛋白水解引发和激活低pH值，以及是否HA 1节段 具有作用，例如在假定的含有多个三聚体的组装中， 毛孔 M2离子通道：生成关于离子通道的结构信息 我们建议在洗涤剂中结晶流感病毒的M2蛋白， 我们已经产生的细菌表达和重折叠的M2四聚体;和/或 通道活性合成跨膜螺旋的四聚体。复合物与 还将研究抑制性药物金刚烷胺。

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.