Simple and Effective Purification of Recombinant Peptide Drug, hPTH (1-34), Expressed in E. coli Host

Abstract

Several human diseases arise from abnormality in functional proteins production in different tissues. Recombinant protein drugs produced in special hosts are the most important solution for this problem. Efficient extraction and purification of recombinant protein from the host proteins is the fundamental stage in recombinant drug manufacture process. Teriparatide, a 34 amino acid peptide, is recombinant FDA approved drug used for osteoporosis stimulates the bone formation and rises its mass. In this research, 6his- E. coli K12β-gal (236-288)-hPTH (1-34) fusion protein was expressed by E. coli BL21 (DE3), extracted with combined chemical and sonication approach led to within 97.7 7% total proteins solubilization. Purification was done during two step chromatography and one enzymatic cleavage for rhPTH (1-34) separation. Approximately, 350 mg of fusion protein was obtained from 1 l culture volume after Ni²⁺ affinity. Enterokinase enzyme was used for fusion protein cleavage and recombinant teriparatide (1-34) was purified by cation exchange HiTrap SP XL chromatography column. Concentration of purified rhPTH (1-34) was estimated about 105 mg/1 l culture. Biological activity of rhPTH (1-34) was analyzed with serum calcium measurement in Vistar rat. The results were shown the rhPTH (1-34) was purified in this research has biological activity as equal as commercial drug. Efficient purification of active rhPTH (1-34) during the two step simple chromatography method is very precious in the industry of recombinant protein production.