Novel four-disulfide insulin analog with high aggregation stability and potency† †Electronic supplementary information (ESI) available: Detailed synthesis procedure and mass spectrometry data along with biological experiment protocol. See DOI: 10.1039/c9sc04555d

• Published in: Chemical science (Cambridge) Vol. 11; no. 1; pp. 195 - 200
• Main Authors: Xiong, Xiaochun, Blakely, Alan, Karra, Prasoona, VandenBerg, Michael A., Ghabash, Gabrielle, Whitby, Frank, Zhang, Yi Wolf, Webber, Matthew J., Holland, William L., Hill, Christopher P., Chou, Danny Hung-Chieh
• Format: Journal Article
• Language: English
• Published: Royal Society of Chemistry 05.11.2019
• Subjects: Chemistry
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/c9sc04555d

A novel four-disulfide insulin analog was designed with retained bioactivity and increased fibrillation stability. Although insulin was first purified and used therapeutically almost a century ago, there is still a need to improve therapeutic efficacy and patient convenience. A key challenge is the requirement for refrigeration to avoid inactivation of insulin by aggregation/fibrillation. Here, in an effort to mitigate this problem, we introduced a 4 th disulfide bond between a C-terminal extended insulin A chain and residues near the C-terminus of the B chain. Insulin activity was retained by an analog with an additional disulfide bond between residues A22 and B22, while other linkages tested resulted in much reduced potency. Furthermore, the A22-B22 analog maintains the native insulin tertiary structure as demonstrated by X-ray crystal structure determination. We further demonstrate that this four-disulfide analog has similar in vivo potency in mice compared to native insulin and demonstrates higher aggregation stability. In conclusion, we have discovered a novel four-disulfide insulin analog with high aggregation stability and potency.