4S-fluorination of ProB29 in insulin lispro slows fibril formation
Loading...
Date
2024
Authors
Breunig, Stephanie L.
Chapman, Alex M.
LeBron, Jeanne
Quijano, Janine C.
Ranasinghe, Maduni
Rawson, Jeffrey
Demeler, Borries
Ku, Hsun Teresa
Tirrell, David A.
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
Recombinant insulin is a life-saving therapeutic for millions of patients affected by diabetes mellitus. Standard mutagenesis has led to insulin variants with improved control of blood glucose; for instance, the fast-acting insulin lispro contains two point mutations that suppress dimer formation and expedite absorption. However, insulins undergo irreversible denaturation, a process accelerated for the insulin monomer. Here we replace ProB29 of insulin lispro with 4R-fluoroproline, 4S-fluoroproline, and 4,4-difluoroproline. All three fluorinated lispro variants reduce blood glucose in diabetic mice, exhibit similar secondary structure as measured by CD, and rapidly dissociate from the zinc- and resorcinol-bound hexamer upon dilution. Notably, however, we find that 4S-fluorination of ProB29 delays the formation of undesired insulin fibrils that can accumulate at the injection site in vivo and can complicate insulin production and storage. These results demonstrate how subtle molecular changes achieved through non-canonical amino acid mutagenesis can improve the stability of protein therapeutics.
Description
Open access article. Creative Commons Attribution 4.0 International license (CC BY 4.0) applies
Keywords
Non-canonical amino acid , Fluoroproline , Proline , Insulin , Insulin lispro , Fibrillation , 4S-fluorination , Protein therapeutics
Citation
Breunig, S. L., Chapman, A. M., LeBon, J., Quijano, J. C., Ranasinghe, M., Rawson, J., Demeler, B., Ku, H. T., & Tirrell, D. A. (2024). 4S-fluorination of ProB29 in insulin lispro slows fibril formation. Journal of Biological Chemistry, 399(6), Article. 107332. https://doi.org/10.1016/j.jbc.2024.107332