Fig. 4

Detection of co-expression of pGH with GroEL–GroES in Pichia pastoris.a SDS–PAGE analysis of soluble protein fractions from Pichia pastoris X33 expressing optimized pGH alone and with GroEL–GroES co-expression. Lanes 1–5, samples of the intracellular supernatant of the co-expressing strain after induction, lane M, the standard molecular weight Marker of 3452 wide type protein, lane 6, the sample of the intracellular supernatant of the co-expressing strain before induction, lane 7, Pichia pastoris X33 of control sample. b Western-blot analysis of soluble protein fractions from Pichia pastoris X33 expressing optimized pGH alone and with GroEL–GroES co-expression. Lanes 1–5, samples of the intracellular supernatant of the co-expressing strain after induction, lane M, the standard molecular weight Marker of 3452 wide type protein, lane 6, the sample of the intracellular supernatant of the co-expressing strain before induction, lane 7, Pichia pastoris X33 of control sample. The G418 concentration of the expression strains of lanes 1–3 was 1.0 mg/mL, the G418 concentration of the expression strains of lanes 4 and 5 was 2.0 mg/mL