Sequential dissociation of insulin amyloids probed by high pressure Fourier transform infrared spectroscopy

High Pressure (HP) Fourier Transform Infrared Spectroscopy (FTIR) has been here employed to investigate the thermodynamic stability of bovine pancreatic insulin (BPI) amyloids. Once the aggregation reaction has started, the backbone arrangement of the proteins forming the amyloid is known to reach a stationary phase in few hours; after this time the infrared absorption of fibrils becomes stable. It is here shown how the further stabilization of the structure during the stationary phase can be probed via FTIR spectroscopy, through the observation of the high pressure behaviour of fibrils formed at different maturation stages. We report on the high pressure fragmentation of insulin amyloids, …