Use of Bacntus brevts for Synthesis Human Insulin Precursor andSecretion of Des-B 30 Single-Chain

A synthetic gene encoding a single chain humall insu1in preeursor [B-chain (1-29)-A-chain] linked to the Cterminai lysine of human epidermal growth factor (1-28) (EGF-SCI) vvas constructed. This gene was expressed using BaciUits brevis. EGF-SCI vvas isolated from the supernatant of the culture broth. Treatment of EGFSCI with lysyl endopeptidase resulted in the formation of des-B30 human insulin. The identrneatioll of the formed des-B30 human insulin was made by the measurement of molecular weight and amino acid analysis. The binding ¢ oeMcient to anti-human insulin antibody