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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 27: INTERNAL SYMPOSIUM Optical Spectroscopy II

CPP 27.3: Vortrag

Donnerstag, 29. März 2007, 15:15–15:30, H40

Proteins under pressure: spectroscopic determination of compressibilities — •Johannes Wiedersich¹, Vladimir Ponkratov¹, Mark Somoza¹, Jane Vanderkoi², and Josef Friedrich¹ — ¹Lehrstuhl für Physik Weihenstephan, Physikdepartment, TU München — ²Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania

By means of optical spectroscopy we determine the local compressibility of proteins. At low temperatures the pressure shift of optical spectra can be precisely determined employing hole burning techniques. The values for the compressibility of ubiquitin and Zn horseradish peroxidase obtained at low temperatures are compared with those from high pressure experiments at ambient temperature. The results of both experiments show the same compressibility, indicating that the compressibility of proteins is the same whether the protein is surrounded by liquid at ambient conditions or whether it is frozen at low temperatures. In both cases the observed values are typical for solids.