Glasses and proteins: Similarities and differences in their spectral diffusion dynamics

We compare the spectral diffusion dynamics of resorufin doped glycerol/H2O- and glycerol/D2O-glass with the respective dynamics of a chromoprotein in the same glass at 4.2 K. Spectral diffusion broadening of photochemical hol es is measured over almost four orders of magnitude in time. In all samples there are strong aging phenomena. Resorufin in deuterated water/glycerol i s reasonably well-described by the two level system (TLS) model. In the pro tonated glass, the TLS model does not seem to describe the experiments reas onably well. In the protein sample it totally fails. (C) 2001 American Inst itute of Physics.