[Expression and synergistic function of ENHANCIN-like gene of Agrotis Segetum granulovirus]

ENHANCIN is an enhancing protein chiefly found in insect baculoviruses. One ENHANCIN homologue was identified, by blast method, in Agrotis Segetum granulovirus (AgseGV) genome, named enhancin-like. Sequence analysis indicated that this gene includes the conserved domains, conserved in other ENHANCIN, and it has no signal peptide or a-transmembrane helix. A proline-rich domain, which is similar to those of mammals, is present at its C-terminal. To analyze the synergistic function of AgseGV enhancin-like gene, prokaryotic expression vectors of its whole gene and the 5'-truncated fragment (1, 017bp) were constructed. Expression product of truncated fragment was purified by chromatography, and then it was used to prepare antibody. The expression product of whole gene was identified by Western blot with specific antibody and anti-His-Tag antibody. Bioassay proved that the expression product of whole gene can increase the mortality with 16.25% to 3th instar larvae of Helicoverpa armigera (HaNPV: 1.17 x 10(2) PIBS/mL), while the truncated fragment has no obvious synergistic function.