Abstract
Elastic properties of the three kinds of polymorphic hen egg white lysozyme crystals with tetragonal, orthorhombic and monoclinic structures are investigated by micro-Brillouin scattering. The temperature dependences of sound velocity and absorption show the variation due to the difference of crystal structure. The temperature dependence of Brillouin scattering of a tetragonal crystal is measured also in the aqueous glycerol solution. The obtained relaxation parameters suggest that hydrated water molecules around a protein molecule are substituted in part for glycerol molecules. The relaxation time obeys the Arrhenius law, and the attempt relaxation rate and the activation energy clearly show the correlation predicted by the Mayer-Neldel rule.
