Regensburg 2002 – wissenschaftliches Programm
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SYBM: Physik biologischer Materie
SYBM 401: Physics of biological matter: Poster
SYBM 401.47: Poster
Dienstag, 12. März 2002, 18:00–19:30, H37
Conformational Fluctuations and Relaxations of Low Temperature Proteins — •Jörg Schlichter and Josef Friedrich — Lehrstuhl für Physik Weihenstephan, Vöttingerstr. 40, 85350 Freising, Germany
We performed a series of hole-burning experiments to investigate the spectral diffusion dynamics of heme-proteins over almost four orders of magnitude in time. The behaviour of these proteins (cytochrome-c, horseradish peroxidase and myoglobin) was measured in different surroundings (water/glycerol- and sugar-glasses) as well as in deuterated samples. In each experiment, spectral holes were burned at different aging times ta. Afterwards, the broadening of these holes was measured as a function of the waiting time tw (i.e. the time span elapsed after the burning of a hole).
In all our experiments, it was possible to scale the results by their ta-dependence, yielding so-called masterplots, whose tw-dependence was always characterized by a power-law with an exponent of about 0.25. An explanation for these results can be given by a model, which holds diffusion-like motions of the amino acid-residues in the proteins responsible for the observed spectral diffusion. In addition, a comparison of the results for different protein-environments and/or deuteration of the samples allows for microscopic interpretations of the experiments.