Abstract: Bioinformatics prediction showed that Gn protein in tomato zonate spot virus（TZSV）is a transmembrane protein consisting of 3 transmembrane domains. Antigen epitope prediction showed that there was a high antigen index region,thus non-transmembrane region of Gn was selected to conduct the prokaryotic expression and to prepare polyclonal antiserum. The Gn gene fragment of TZSV was amplified from TZSV-infected tomato sample by RT-PCR,and then cloned into prokaryotic expression vector pET-30a. The recombinant plasmids pET-30a-Gn were transformed into Escherichia coli BL21（DE3）,and then induced to express with IPTG. The result of SDS-PAGE analysis showed the specific fusion protein with molecular weight of 40 kD was highly expressed. Using the purified fusion protein,rabbit was immunized to obtain polyclonal antiserum against TZSV Gn protein. The titer of antiserum was 1/16384 determined by ID-ELISA. The specific band was detected by Western blot while applying the prepared antiserum to the TZSV-infected samples. These results reveal that the specificity of the antiserum is fine,and it is applicable for immune-reaction test related to TZSV Gn.

Key words: tomato zonate spot virus, Gn protein, prokaryotic expression, antiserum