Structural Analysis of BVDV Non-structural Protein NS4B and Protein Expression and Identification
NS4B is a nonstructural protein of Bovine viral diarrhea virus(BVDV).In order to study its function in the process of BVDV infecting host cells,we analyzed the structure of ns4b,constructed the expression vector and expressed NS4B protein.The amino acid composition,hydrophobicity and spatial structure of BVDV ns4b were analyzed by Prot-Param,TExpasy and SignalP-4.1.The ns4b gene was obtained by PCR using primers designed according to the sequence of BVDV ns4b gene published in Genebank,the recombinant plasmids p3×Flag-CMV10-ns4b were constructed and identified by restriction enzyme digestion and sequencing.The recombinant plasmids p3×Flag-CMV10-ns4b were transfected into HEK-293T cells,and the expression of NS4B protein was detected by Western blot.The results showed that the molecular weight of BVDV NS4B protein was 38.4 kDa,there was no signal peptide,but 49 phosphorylation sites,6 glycosylation sites,α-helix and random coil structure about NS4B as a hydrophobic protein.In addition,the recombinant plasmids p3×Flag-CMV10-ns4b were successfully constructed and expressed in HEK-293T cells.These results provided an important foundation for the further research of BVDV infection and immune escape mechanism mediated by NS4B protein.