Figure 1

Successful expression of PprI in Pichia pastoris.

(a) SDS-PAGE analysis of cultural supernatant taken from Pichia pastoris transformants induced with l% methanol for 3 days. Lane 1: plasmid pHBM905A transformed into Pichia pastoris strain GS115 (negative control). Lanes 2–9: Pichia pastoris strain GS115 cells NO. 1–NO. 8 transformed with pHBM905A-6 × His-pprI. (b) Western blot detection of the expression product taken from Pichia pastoris transformants. Lane 1: cultural supernatant of NO. 2 yeast transformant that was induced for 2 days. Lane 2: cultural supernatant of NO. 3 yeast transformant that was induced for 2 days. Lane 3: cultural supernatant of NO. 3 yeast transformant that was induced for 1 day. (c) PMF mapping. (d) The expressed and purified fusion protein PprI was analyzed using 12% SDS-PAGE followed by Coomassie Blue staining. Lane M: protein marker. Lane 1: supernatant after dialysis. Lane 2: flow through. Lane 3: elution fractions of 50 mM Tris, 300 mM NaCl, 20 mM Imidazole, pH 8.0. Lanes 4: The first elution fractions of 50 mM Tris, 300 mM NaCl, 250 mM Imidazole, pH 8.0. Lanes 5: The second elution fractions of 50 mM Tris, 300 mM NaCl, 250 mM Imidazole, pH 8.0.