Objective To express the His-tag recombinant proteins encoded by a series of fragments of hepatic C virus (HCV) gene and to explore the significance of the proteins in the detection for anti-HCV antibodies.Methods Three recombinant plasmids [C-pET-28a-c (+),NS3-pET-28a-c (+) and NS4-pET-28a-c(+)] were constructed using the techniques of gene engineering.The recombinant plasmids were confirmed by PCR,endonuclease splicing and sequencing.Three His-tag recombinant antigens (H-C,H-NS3 and H-NS4) were expressed by the induction of IPTG and purified with Ni2+-NTA resin,which were applied for ELISA detection of anti-HCV antibodies.100 serum samples which were known to be anti-HCV-positive were tested with each of the three antigens and the mixed proteins.40 specimens collected from healthy persons were also tested with the antigens.Results The positive rates of anti-C,anti-NS3,and anti-NS4 in the anti-HCV-positive sera were 91%,75%,and 52%,respectively.However,all the anti-HCV-positive sera were immunoreactive to the mixed antigens,and all the specimens obtained from healthy persons did not react to the antigens.Conclusions There are different immunoreactivities of the His-tag recombinant antigens encoded by different gene fragments.The mixture of all the antigens derived from HCV different encoding regions should be applied in further HCV diagnostic test to detect anti-HCV antibodies. |
