Novel four-disulfide insulin analog with high aggregation stability and potency.
Xiong, X., Blakely, A., Karra, P., VandenBerg, M.A., Ghabash, G., Whitby, F., Zhang, Y.W., Webber, M.J., Holland, W.L., Hill, C.P., Chou, D.H.(2020) Chem Sci 11: 195-200
- PubMed: 32110371 
- DOI: https://doi.org/10.1039/c9sc04555d
- Primary Citation of Related Structures:  
6TYH - PubMed Abstract: 
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.
Organizational Affiliation: 
Department of Biochemistry , University of Utah , Salt Lake City UT 84112 , USA . Email: chris@biochem.utah.edu ; Email: dchou@biochem.utah.edu.