中国生物工程杂志

The role of conserved insulin residues TyrB26 was studied to better understand the relationship between insulin and its receptor. Insulin analogues with a single amino acid substitution or single N-methylation of the peptide bond in the position B26 were all shortened in the C-terminus of the B-chain by four amino acids. The effect of modifications was followed by the binding to the human insulin receptor. From our results: [HistidineB26]-des-tetrapeptide-(B27-B30)-insulin -B26-amide and [N-MeHisB26]-des-tetrapeptide-(B27-B30)-insulin-B26-amide had no significant effect on the binding affinity and they showed binding affinity 72 and 107 % of that of human insulin respectively; [N-MeGluB26]-des-tetrapeptide-(B27-B30)-insulin-B26-amide, [AadB26]-des- tetrapeptide-(B27-B30)-insulin-B26-amide and [Phe(4-carboxyB26)]-des-tetrapeptide-(B27-B30)– insulin-B26-amide affected the potency highly positively in vitro studies; they showed binding affinity 130, 234, 160%, respectively, of that of human insulin.