3-D STRUCTURES OF VIRAL ANTIGEN-ANTIBODY COMPLEXES

该项目的目的是巩固关于 流感病毒神经氨酸酶和流感病毒的三维结构 两种抗体分子(NC41和NOLO)与人免疫球蛋白的结合 流感病毒抗原神经氨酸酶。这是一个延续 NIH拨款A121659支持的工作。 具体来说，将开展三项工作。 (1)NC41 Fab-神经氨酸酶的结构 将根据可用的X射线衍射法定义络合物 数据分辨率为2.8A。将对生成的结构进行分析 的构象变化的准确描述 神经氨酸酶被认为伴随着这个结合 特异性抗体(NC41)，并试图寻找一种结构 当抗体出现时，酶活性下降的相关性 捆绑。改进还将允许准确地描述 FAB片段中的V-模四元结构，它具有 据报道是不寻常的。由于VL和VL的不常见配对 在复合NC41抗体情况下观察到的VH结构域 可能是由抗原诱导的，细节上的差异 此FAB结构与其他FAB结构之间可以提供一些基本的 对免疫识别的洞察。 (2)NClO Fab-神经氨酸酶复合体的结构为 坚定而精致。来自此结构的发现将添加 到关于抗体-抗原复杂结构的非常小的数据库， 并有助于澄清适应性配件的相对重要性 与刚性结合在这一重要类别的形成中 大分子复合体。 (3)神经氨酸酶逃逸突变体的结构如下 已完成的与其他单抗的结晶实验 抗体和甲型流感病毒神经氨酸酶将继续存在。 从这项工作中产生的知识将(A)允许 该流感病毒两个重叠表位的描述 抗原，(B)增加了我们对抗原变异的理解 这种病毒和其他可变病毒(如艾滋病毒)，(C)有助于提供 对免疫识别的一般理解，至少在 B细胞免疫，以及(D)有助于未来合理设计 合成疫苗。

The aim of this project is to consolidate preliminary studies on the 3-d structures of influenza virus neuraminidase and of complexes between two antibody molecules (NC41 and NOlO) and the influenza virus antigen neuraminidase. It is a continuation of work supported under NIH grant A121659. Specifically, three tasks will be undertaken. (1) The previously determined structure of NC41 Fab-neuraminidase complex will be defined against the available X-ray diffraction data to 2.8A resolution. The resulting structure will be analyses to enable an accurate description of conformational changes in the neuraminidase which are believed to accompany the binding of this particular antibody (NC41), and to attempt to find a structural correlate of the decrease in enzyme activity when the antibody binds. The refinement will also permit an accurate description of the V-module quaternary structure in the Fab fragment, which has been reported to be unusual. Since the uncommon pairing of VL and VH domains observed in the case of the complexed NC41 antibody might have been induced by antigen, the detailed differences between this and other Fab structures may provide some fundamental insights into immune recognition. (2) The structure of NClO Fab-neuraminidase complex will be determined and refined. The findings from this structure will add to the very small database on antibody-antigen complex structures, and help to clarify the relative importance of adaptable fitting versus rigid bonding in the formation of this important class of macromolecular complexes. (3) The structures of escape mutants of neuraminidase will be completed and crystallization experiments with other monoclonal antibodies and influenza A virus neuraminidases will continue. The knowledge generated from this work will (a) permit a description of two overlapping epitopes of this influenza virus antigen, (b) add to our understanding of antigenic variation in this and other variable viruses (such as HIV), (c) help to provide a general understanding of immune recognition, at least as regards B cell immunity, and (d) aid in the future rational design of synthetic vaccines.