Cloning and expression of the envelope gene fragment from human immunodeficiency virus 1 in Saccharomyces cerevisiae
Objective To acquire enough envelope glycoproteins so as to facilitate a further study of the structure and function of envelope glycoproteins from various kinds of virus isolates. Methods Two envelope glycoprotein gene fragments were cloned from the recombinant plasmid pHXB2 containing the human immunodeficiency virus 1(HIV 1) proviral genome of HXB2 isolate. Two corresponding expression plasmids pYENV1 and pYENV2 were constructed using a yeast shuttle inducible expression vector pYES2 Furthermore plasmid pYENVG12 with the fused gene cassette between external envelope gene fragment and β lacZ gene was constructed. These three plasmids were transformed into the unicellular eukaryotic S. cerevisiae BJ1991 and the galactose induced transformants were analyzed with the SDS PAGE. Results The result showed that a 50kD specific protein induced from the transformant containing the fused plasmid was shown to have antigenic reactivity with HIV 1 antibodies positive sera by immunodetection. Conclusions Therefore not only could the expression of the antigenic fragment be directly indicated by the β galactosidase activity, but also it laid some foundation for further purification of the fragment of the expressed envelope glycoproteins.