The road to the first, fully active and more stable human insulin variant with an additional disulfide bond

TY - JOUR

T1 - The road to the first, fully active and more stable human insulin variant with an additional disulfide bond

AU - Vinther, Tine N.

AU - Kjeldsen, Thomas B.

AU - Jensen, Knud Jørgen

AU - Hubálek, František

N1 - Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd.

PY - 2015/11/1

Y1 - 2015/11/1

N2 - Insulin, a small peptide hormone, is crucial in maintaining blood glucose homeostasis. The stability and activity of the protein is directed by an intricate system involving disulfide bonds to stabilize the active monomeric species and by their non-covalent oligomerization. All known insulin variants in vertebrates consist of two peptide chains and have six cysteine residues, which form three disulfide bonds, two of them link the two chains and a third is an intra-chain bond in the A-chain. This classical insulin fold appears to have been conserved over half a billion years of evolution. We addressed the question whether a human insulin variant with four disulfide bonds could exist and be fully functional. In this review, we give an overview of the road to engineering four-disulfide bonded insulin analogs. During our journey, we discovered several active four disulfide bonded insulin analogs with markedly improved stability and gained insights into the instability of analogs with seven cysteine residues, importance of dimerization for stability, insulin fibril formation process, and the conformation of insulin binding to its receptor. Our results also open the way for new strategies in the development of insulin biopharmaceuticals.

AB - Insulin, a small peptide hormone, is crucial in maintaining blood glucose homeostasis. The stability and activity of the protein is directed by an intricate system involving disulfide bonds to stabilize the active monomeric species and by their non-covalent oligomerization. All known insulin variants in vertebrates consist of two peptide chains and have six cysteine residues, which form three disulfide bonds, two of them link the two chains and a third is an intra-chain bond in the A-chain. This classical insulin fold appears to have been conserved over half a billion years of evolution. We addressed the question whether a human insulin variant with four disulfide bonds could exist and be fully functional. In this review, we give an overview of the road to engineering four-disulfide bonded insulin analogs. During our journey, we discovered several active four disulfide bonded insulin analogs with markedly improved stability and gained insights into the instability of analogs with seven cysteine residues, importance of dimerization for stability, insulin fibril formation process, and the conformation of insulin binding to its receptor. Our results also open the way for new strategies in the development of insulin biopharmaceuticals.

U2 - 10.1002/psc.2822

DO - 10.1002/psc.2822

M3 - Review

C2 - 26382042

SN - 1075-2617

VL - 21

SP - 797

EP - 806

JO - Journal of Peptide Science

JF - Journal of Peptide Science

IS - 11

ER -