Master thesis defense:
Investigating the role of water in the protein dynamic transition
Chemical Physics, Stockholm University
Proteins undergo a dynamic transition at approximately 220 K, also called protein ’glass’ transition, below which temperature proteins lose their conformational flexibility and become biologically inactive. Water seems to play a role in this transition, especially in relation to the hydration layer surrounding the protein, termed hydration water. Despite various interpretations that have been advanced, the origin of the protein dynamic transition is still elusive. Here, we present our investigation of the protein ’glass’ transition by means of infrared spectroscopy and X-ray diffraction probing lysozyme over the temperature range 160- 295K and discuss the data in connection to the different hypothesis proposed.