Purification of Glutathione S-transferase Fusion Proteins of SARS Coronavirus Spike Protein ragment 2 and Preparation of Anti-GST-S2 Polyclonal Antibody

Our previous studies showed that the NSP4 gene of human rotavirus epidemic strains in China can be divided into two groups:Wa and Kun, and the Wa group contains three subgroups. To investigate whether there were differences in virulence among the different rotavirus NSP4 genotypes, NSP4 genes from different genetic types were expressed in recombinant baculoviruses using Bac-to-Bac expression system and four recombinant baculoviruses were obtained. Compared with the mock infected cells or the wild type baculovirus AcNPV infected cells, the intracellular Ca 2+concentration increased 5.24, 5.43, 5.34 and 5.45 folds at 72h post infection, respectively. However, there was no significant difference among the increasing of intracellular calcium level induced by the four recombinant baculoviruses. On the basis of the above results, the recombinant NSP4 proteins from Wa or Kun groups were expressed in E.coli and purified ,and the diarrhea induction activity was tested in sucking mice model. The results showed that dia