Prokaryotic expression and identification of nucleocapsid gene of Canine Distemper Virus CDV-FOX-TA strain from Fox
狐源犬瘟热病毒CDV-FOX-TA株核蛋白基因的原核表达及鉴定

The high conservative sequence of Canine Distemper Virus (CDV) N gene was amplified with RT-PCR, cloned into pMD18-T vector , and then constructed into upstream site of His Tag coding sequence in prokaryotic expression vector pET24b. The N fusion protein was highly expressed when the recombinant plasmid was transformed E coli Rosetta 2(DE3) strain and induced with IPTG. SDS-PAGE and Western blot showed the 15kD expressed products reacted with standard positive serum against CDV. An indirect ELISA demonstrated recombinant expressed protein had good antigencity and can distinguish effectively anti-CDV positive serum and negative serum. The results showed expressed CDV N protein had similarity of antigencity with natural N protein, and can be used as diagnosis antigen. It provided evidence for establishment of an indirect ELISA method for CDV detection.