Dielectric relaxation, rotational diffusion and the heat denaturation transition in aqueous solutions of RNAse A

The heat denaturation transition of pancreatic RNAse A was investigated by time-domain spectroscopy. In the temperature interval 5-90°C the protein molecule may be in three states: native, temperature denaturated and unfolded. The heat denaturation process occurs in two stages: In the first stage the system behaves as a macromolecule, maintaining its globular structure and increasing its volume two times and its dipole moment 1.5 times; in the second stage the transition into a statistical coil state Occurs.