Proteins and glasses: A comparative study of spectral diffusion phenomena

Abstract

We compare the spectral diffusion broadening of mesoporphyrin substituted horseradish peroxidase with the chromophore doped host glass. Whereas the broadening in the glass is smooth and follows a power law with an exponent close to (3)/(2), there is a a steplike broadening in the protein which occurs around 14 K. The observed phenomena are interpreted on the basis of a two domain interaction of the chromophore with its environment.