Cloning of the structural gene for hepatitis B virus surface antigen into a yeast vector

Abstract

The structural gene of hepatitis B virus surface antigen (HBsAg) was cloned into a shuttle vector pAAR 6 which is capable of autonomous replication and selection in both of the yeast Saccharomyces cerevisiae and Escherichia coli. This expression vector employs the 5'-flanking region of ADC I gene as a promoter in order for transcribing viral surface antigen coding sequences. After transformation of the recombinant plasmid into yeast strains such as SHY 3, YNN 27, D 13, ATCC 38517 and ATCC 42677, the expression of HBsAg gene in the host cells was evident. The protein synthesized in yeast cells was found to be similar in size, density and shape to the 22 nm particles isolated from the nlasma of human heDatitis carriers.