EXPRESSION OF THE TICK-BORNE ENCEPHALITIS-VIRUS NS3 GENE IN ESCHERICHIA-COLI

A full-length DNA copy of the NS3 protein gene of tick-borne encephalitis virus (TBEV) has been constructed from two overlapping cDNA clones and a set of synthetic DNA fragments, and expressed in Escherichia coli. The relatively low level of biosynthesis of the full-length NS3 protein is due to the toxicity of the N-terminal portion of the protein comprising the first 180 amino acids. A truncated form of the NS3 gene (NS3*) was constructed and was expressed efficiently in a bacterial procedure strain. A panel of monoclonal antibodies to the TBEV non-structural proteins NS1 and NS3 has been obtained. Based on the binding of antibody 18B2 to the bacterial products of the NS3 and NS3* genes it is concluded that the antigenic determinant recognized by this antibody is located between amino acid residues 174 and 236 of the NS3 protein.