Stabilizing protein pharmaceuticals by imidazolium-type zwitterions.

An imidazolium-carboxylate-type zwitterion, OEimCC, thermally stabilizes the structure in the vicinity of heme in cytochrome . However, it remains unclear whether OEimCC can thermally stabilize protein pharmaceuticals, which are vulnerable to heating and shaking during production and transportation. In this study, we investigated the stabilization of the entire structure and function of insulin by OEimCC.