HIGH-LEVEL PRODUCTION AND ONE-STEP PURIFICATION OF BIOLOGICALLY-ACTIVE HUMAN GROWTH-HORMONE IN ESCHERICHIA-COLI

A plasmid has been constructed to direct the synthesis of recombinant human growth hormone (re-hGH) in Escherichia coli as a fusion protein containing a His(6) tag at the N-terminus under the control of the T5 promoter. The re-hGH was synthesized in large amounts and accumulated in the form of inclusion bodies upon induction with IPTG. Inclusion bo dies were solubilized in 6 M guanidine-HCl and the re-hGH was purified by single-step affinity chromatography on Ni2+-nitrilotriacetic acid (NTA) agarose. At the shake flask level, the purified re-hGH was obtai ned with a yield of 30 mg/l of culture. The re-hGH was biologically ac tive in a node rat lymphoma (Nb-2) cell bioassay.