Cloning And Expressing S2 Gene Of SARS-CoV And Studying On Antigenic Activities Of S2 Protein

Background and objectiveSevere acute respiratory syndrome (SARS), described as an "infectious atypical pneumonia", is a new emerging disease. SARS-CoV is divided into Nidovirales, Coronaviridae Coronavirus. Its genome is a single-strand positive sense RNA, and its genome all-length about 29.7kb.Now we have known that SARS-CoV encoded 11 varietal proteins. They have 4 constitutive proteins: spike protein, membrane protein, envelope protein and nucleocapsid protein. Spike protein trimer form spike and exsertion? virus peplos on the surface. Spike protein is archi-surface antigen component of virus, it has acceptor binding and membrane fusion activity. Spike protein has important effect at tissue tropism, cell-fusion and toxicity. Nucleocapsid protein can bind genome RNA to shape neucleocapsid. Membrane protein and envelope protein are necessary constituent to shape virus peplos.Spike protein is I-type membrane glycoprotein, it mediate virus binding with host cell epimembranal acceptor and to fuse host cell membrane. Spike protein consists of S1 and S2 subunit. S1 is head and S2 is rod-shape part, intermolecular effort can bind each other. S1 can bind with host cell epimembranal acceptor. S2 can fix integral Spike protein on the cellular membrane and mediate cell-fusion with virus and host cell. There are significant antigen determinant of virus in Spike protein, genic heterogenesis can effect viral pathogenicity. SARS-CoV Spike protein, which has 23 pieces larvaceous glycosylation sit, consists of 1256 amino acid. Its N-terminals and C-terminals is corresponding conservative. N-terminals has a hydrophobicity amino acid which compose with signal peptide and its shearing point possible located at 13 or 14 location amino acid. It can assist virus to hold on endocytoplasmic reticulum. C-terminals compose with high conservative transmembrane domain and are rich in aminothiopropinonic acid residue. Main part...