Protein Stability Studied by Infrared Spectroscopy

ABSTRACTInfrared structural analysis usually implies a mathematical approach to extract the information contained in the protein amide bands. Thermal profiles have been used to help in the understanding of protein stability. A new approach, generalized 2D- IR correlational spectroscopy, has been recently introduced. This approach performs a correlation analysis of the dynamic fluctuations caused by an external perturbation, to enhance spectral resolution. By using a combination of these three approaches we have studied the thermal unfolding of several soluble and membrane proteins showing that the various secondary structure elements unfold at different temperatures showing a different stability, which is more dependent on the protein topology rather than on secondary structure.