Overexpression for commercial production of recombinant human insulin as A-chain and B-chain fusion protein in Escherichia coli through genetically engineered plasmids.

ABSTRACT

The construction of expression vectors encoding either the human insulin A- or B-chains fused to a synthetic peptide and the temperature-induced expression of the recombinant genes in Escherichia coli are reported. Using this two-chain approach we also describe the separate isolation of the insulin A- and B-chains from inclusion bodies and their subsequent assembly into native human insulin. The expression yields about 600 mg of the insulin B-chain per litre of culture. Under similar conditions the expression yield of the insulin A-chain corresponds to approximately 500 mg per litre of culture. This is the highest yield from shake flask experiments.