Expression of hepatitis B surface antigen in Saccharomyces cerevisiae utilizing glyceraldeyhyde-3-phosphate dehydrogenase promoter of Pichia pastoris.

An expression vector constructed from genes of Pichia pastoris was applied for heterologous gene expression in Saccharomyces cerevisiae. Recombinant hepatitis B surface antigen was synthesized by cloning hepatitis B virus 'S' gene under the control of glyceraldehyde-3-phosphate dehydrogenase (GAP) promoter of Pichia pastoris in Saccharomyces cerevisiae. Hepatitis B surface antigen was constitutively expressed, was stable and exhibited approximately 20-22 nm particle formation. Stability and absence of toxicity to the host with the expression vector indicates the expression system can be applied for large-scale production.