Study on the Expression, Purification and Activity of Arginine Deiminase / 中国生物工程杂志

ABSTRACT

Objective: To develop a high efficient expression, purification system of recombinant arginine deiminase(ADI).Methods: cDNA fragment encoding for mycoplasma ADI was obtained by artificial synthesis and was cloned into prokaryotic expression vector(pBV220). The recombinant ADI was generated by the transformation of the recombinant vector into the host strain DH5?. Anion exchange and gel filtration chromatography was carried out for purification of the recombinant ADI. The biological activity of final product was detected by the assay of agrinine degradation in vitro. Results: A prokaryotic expression plasmid pBV220-ADI was generated successfully, and was identified by DNA sequencing; the recombinant protein was highly expressed in DH5?, the proportion of the recombinant protein is exceeded 35% of the whole protein. The inclusion bodies were solubilized with 6mol/L guanidine hydrochloride under reducing conditions in order to avoid incorrect disulfide-bond formation of the recombinant ADI molecules. Dilution and dialysis at lower degrees temperature were the optimum renaturation methods. After gel filtration, the purity and specific activity of rADI reached 95% and 80 IU/mg respectively. Conclusions: A set of protocols for high efficient rADI expression and purification has been established, which is simple, efficient and applicable.