Raman spectroscopic and low temperature calorimetric investigation on the low energy vibrational dynamics of hen egg-white lysozyme

Cristina Crupi (1) , Giovanna d'Angelo (2) , Cirino Vasi (3) , Ulderico Wanderlingh (1)

1 Physics
2 physics
3 IPCF - CNR Istituto per i Processi Chimico-Fisici

We have investigated the low frequency vibrational dynamics of chicken hen egg-white lysozyme using Raman spectroscopy and low temperature calorimetry. An amorphous-like behaviour of low frequency dynamics in this protein has been observed. By using inelastic light scattering data and resorting to a fitting procedure, the low temperature specific heat trend has been theoretically reproduced confirming that, as in disordered systems, the same low energy excitations give rise to the observed anomalies in low frequency vibrational and low temperature thermal properties. A further study of polarized and depolarized Raman spectra has allowed us to infer information about the symmetry of these modes. A linear trend for the light-vibrations coupling constant has been found which underlines a further similarity between amorphous systems and proteins.

Mots clés: Physical Sciences

Cristina Crupi, Giovanna d'Angelo, Cirino Vasi, Ulderico Wanderlingh. Raman spectroscopic and low temperature calorimetric investigation on the low energy vibrational dynamics of hen egg-white lysozyme. Philosophical Magazine, 2011, pp.1. ⟨10.1080/14786435.2010.535035⟩. ⟨hal-00658696⟩