Fig. 3

Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) and western blot analysis of rHlFBA. a SDS-PAGE of rHlFBA protein expression in cells of Escherichia coli BL21 strain induced by 0.5 mM isopropyl-β-d-1-thiogalactopyranoside (IPTG) at 25 °C. Lanes: 1 Production of the rHlFBA protein without IPTG; 2, 3, 4, 5 production of rHlFBA protein in the supernatant with IPTG at 25 °C for 2, 4, 6 and 8 h, respectively; M marker; 6, 7, 8, 9 production of the rHlFBA protein in the precipitation with IPTG at 25 °C for 2, 4, 6 and 8 h, respectively. b SDS-PAGE analysis of rHlFBA protein elution. Lanes: M Marker; 1 production of the rHlFBA protein with IPTG induction; 2–6 rHlFBA protein eluted with 20 mM, 50 mM, 100 mM, 200 mM and 500 mM imidazole, respectively. c Western blot analysis of the rHlFBA protein. Lanes: M Marker; 1 purified rHlFBA by Ni column incubated with rabbit anti-H. longicornis serum; 2 IPTG-induced E. coli with pET-32a(+)-HlFBA incubated with rabbit anti-H. longicornis serum; 3 purified rHlFBA by Ni column incubated with rabbit negative serum. Arrows indicate the rHlFBA protein. rH1FBA, Recombinant fructose-1,6-bisphosphate aldolase from Haemaphysalis longicornis