Human epidermal growth factor excreted by recombinant Escherichia coli K-12 has the correct N-terminus and is fully bioactive

The high stability and productivity of recently-developed Escherichia coli JM101 strains expressing human epidermal growth factor (hEGF) facilitated s cale-up of hEGF production, and a protocol to purify hEGF from bacterial cu lture supernatant was developed. hEGF-containing supernatant from an induce d hEGF-expressing recombinant E. coli culture was purified by: (A) QAE Seph adex A-25 ion-exchange chromatography; (B) Sephadex G-25 desalting; (C) SP- Sepharose cation-exchange chromatography; and (D) reverse-phase HPLC. The h EGF obtained was pure by HPLC and SDS-PAGE. The N-terminus of the purified hEGF was authentic. Commercial pure hEGF, and hEGF purified as described, w ere assessed for bioactivity, and yielded superimposable curves. The recove ry of hEGF with this protocol was 30% of original, while the purity was 97- 100%. (C) 1999 Elsevier Science Ltd. All rights reserved.