the od550 reached 0 5 1 after the od550 was around 0 5 1 protein expression was induced with isopropylthiogalactoside iptg at concentration of 0 5 mm after an incubation time of 6 h at 37 u00b0 c the cells were harvested by centrifugation and resuspended in 50 ml pbs containing 100 u03bcg ml lysozyme ph 7 5 store the suspension at 4 u00b0 c for 30 min and then the suspension were sonicated on ice 15 u00d7 1 5 s pulses with 1 s intervals and centrifuged for 10 min at 10000 g the precipitate was resuspended in 50 ml ib wash buffer 20 mm tris hcl ph 7 5 10 mm edta 1 triton x 100 and centrifuged again at 10000 g for 10 min repeat this step three times and the inclusion body containing precipitate of pet24a hscf ii bl21 codon plus was suspended in 25 ml 6 m gn hcl buffer containing 20 mm tris hcl 0 5 m nacl ph 7 8 store the suspension at 4 u00b0 c for overnight to dissolve the inclusion bodies residual insoluble matter was removed by centrifuging at 15000 g for 30 min the resulted protein solution was loaded onto a his bind resin column after loading the sample the purified protein was eluted by elute buffer 8 m urea 20 mm tris hcl 0 5 m nacl 0 25 m imidazole ph 7 8 the purified protein solution was diluted with 9 volumes of rapid refolding buffer 2 5 m urea 20 mm tris hcl 0 01 mm edta 2 mm gsh 0 2 mm gssg 0 02 sodium azide 0 2 m arginine ph 8 5 after 48 h.