Expression of recombinant human parathyroid hormone(1-34)induced by lactose

Objective To investigate the feasibility of expression of recombinant human parathyroid hormone induced by lactose instead of IPTG.Methods The influences of inducer concentration,induction time and culture method of fermentation were investigated to determine the optimal induction conditions.Results The target protein was about 56.8% of total cellular proteins with 0.6% lactose at 4 h,and the expression level reached about 42.6% in 5 L fermentor with fed-batch culture.Conclusion Lactose could be used as inducer in the expression of rhPTH(1-34) in Escherichia coli.