副粘病毒是人类及动物的重要致病病毒。病毒包膜与宿主细胞膜的融合和细胞之间的膜融合是副粘病毒感染宿主细胞的关键步骤和重要病理特征，此过程是在同源性血凝素-神经氨酸酶（HN）协助下，由病毒包膜融合蛋白（F）介导下完成的。连接区是F蛋白结构域连接的桥梁和纽带，同时也是结构域相互传递信息的通路。目前认为，HR1与HR2之间的区域（包括D1，D2，D3结构域和连接区L1，L2和L3）与融合肽存在相互作用，D1，D2和D3区域内的保守氨基酸对F蛋白介导细胞融合功能至关重要。而连接区在F蛋白介导细胞融合过程中发挥何种作用尚不清楚。本课题拟以人副流感病毒3型（hPIV3）和新城疫病毒（NDV）为模型，通过连接区缺失、突变和替代三种方法研究F蛋白三个连接区在F蛋白介导细胞融合机制中的作用。同时拟设计含有连接区L1的合成肽，在为研究合成肽抗病毒作用机制提供新思路的同时，进一步探索细胞融合的发生机制。

Paramyxoviruses are important pathogenic viruses for human beings and animals. The entry of paramyxoviruses into cells requires the merger of viral and cellular membranes and formation of cell fusion is a key pathological characteristic of viral infection. For most paramyxoviruses, the fusion protein(F) alone cannot mediate fusion; it requires coexpression of the homologous haemagglutinin-neuraminidase protein. A linkage is not only the bridge and tie between domains of F protein, but the channel of information transmission between them. The domain between HR1 and HR2 interacts with the fusion peptide. It has also been found that conserved amino acids in three domains, D1, D2 and D3, play an important part in F protein-mediated membrance fusion. However, it has not been reported whether the linkages impact on F protein-mediated membrance fusion or not. To explore the role of linkages in F protein-mediating membrance fusion, we are going to study the function of three linkages of F protein，using human parainfluenza virus type 3(hPIV3) and Newcastle disease virus(NDV) as models, by deleting, mutating and substituting amino acids in the linkages. Meanwhile, we are going to design synthetic peptides containing L1 to provide a new strategy for studying antiviral mechanism by synthetic peptides and further to know the mechanism of cell fusion.