Protein engineering of insulin: Two novel fast-acting insulins [B16Ala]insulin and [B26Ala]insulin

Blood glucose lowering assay proved that B16Ala]insulin and B26Ala]insulin exhibit potency of acute blood glucose lowering in normal pigs, which demonstrates that they are fast- acting insulin. Single-chain precursor of B16Ala]insulin and B26Ala]insulin is B16Ala]PIP and B26Ala]PIP, respectively, which are suitable for gene expression. Secretory expression level of the precursors in methylotrophic yeast Pichia pastoris was quite high, 650 mg/L and 130 mg/L, respectively. In vivo biological assay showed that the two fast-acting insulins have full or nearly full biological activity. So both B16Ala]insulin and B26Ala]insulin can be well developed as fast-acting insulin for clinic use.