Temperature- and pressure-induced unfolding of ubiquitin

Temperature- and pressure-induced denaturation of the protein ubiquitin was investigated using Fourier-transform infrared (FTIR) spectroscopy. On the basis of IR spectral parameters, different states are distinguished and a tentative stability diagram of the protein is presented. Features of the secondary structure remain distinct at high pressure and part of the protein restructures. Contrary to the case for temperature denaturation, the secondary structure changes during compression and decompression are fully reversible and no aggregation occurs.