A study on expression level of DNA recombinant intracellular HBsAg in Pichia pastoris

ABSTRACT

Two positive clones inserted DNA fragment of HBV coded for intracellular HBsAg synthesis from 2 strains of P.pastoris GS115-47-4 (Mut+ His 4) and KM71-47-1 (Muts; His4 arg4 aox1 ARG4) were selected for developing a DNA recombinant hepatitis B vaccine in laboratory scale. Different types of growth media and expression media were used for the study on HBsAg expression levels from those two clones. The highest level of HBsAg - 1318mcg/l with MGYH/MMH medium after 96h and 2220 mcg/l with BMGY/BMMY medium after 72h of induction was obtained in clone GS115-47-4 and 241 mcg/l after 48h and 1680 mcg/l after 48h in clone KM71-47-1 observed were respectively.