Semisynthesis of A6-A11 lactam insulin

Area of Science:

• Biochemistry
• Medicinal Chemistry
• Endocrinology

Background:

• Insulin replacement therapy is crucial for diabetes management, but improving glycemic control and patient quality of life remains a challenge.
• Research is focused on developing orally available, glucose-responsive, and rapid-acting insulins.
• Formulation stability of insulin analogues can be enhanced by replacing the native A6-A11 disulfide bond with stable mimetics.

Purpose of the Study:

• To demonstrate the proof of principle for the semisynthesis of insulin analogues with nonnative A6-A11 cystine isosteres.
• To develop a scalable and cost-effective synthetic strategy for producing insulin analogues with improved stability.
• To explore a new approach for creating hyperstable proteomimetics.

Main Methods:

• Semisynthesis of insulin analogues utilizing biosynthetically derived peptide precursors.
• Incorporation of a chemically synthesized A6-A11 macrocyclic lactam fragment.
• Evaluation of the biological activity of the assembled insulin analogue.

Main Results:

• A novel semisynthetic strategy for insulin analogues bearing nonnative A6-A11 cystine isosteres was established.
• The synthetic approach uses cost-effective, scalable peptide precursors and a chemically synthesized lactam fragment.
• The resulting A6-A11 lactam insulin analogue showed poor in vitro biological activity.

Conclusions:

• The developed semisynthetic strategy is applicable to other disulfide mimetics that enhance thermal stability without compromising activity or structure.
• This approach provides a foundation for a new generation of hyperstable proteomimetics.
• Further research is needed to optimize the biological activity of these modified insulin analogues.