Expression of p19 Gene of Avian Leukosis Virus in Escherichia coli / 中国病毒学

Based on avian leukosis virus ( ALV) p19 gene terminal nucleotide sequence, a 82 bp double-stranded DNA fragment was chemically synthesized and cloned into the expression vector pGEMEX-1. The sequencing result indicated th at the cloned fragment was a correct version of the one designed both in nucleot ide sequence and in its open reading frame. The recombinant was used to transfor m E.coli BL21 (DE3). The cloned fragment was expressed as a fused protein wi th T7 gene 10 leader peptide and was shown to be 34 kD in size on SDS-PAGE gel when induced with 1 mmol/L IPTG. The expression product was able to bind immunol ogically to rabbit anti-ALV serum in Western-blot assay and is being tested to differentiate exogenous from endogenous ALV.