| Regional Biophysics Meeting 2005, March 16-20, Zreče, Slovenia | [ProtBiophys] |
Pressure is known to change the structure of the proteins. Mild pressures cause only reversible elastic effects, allowing the determination of the elastic properties of the proteins. The compressibility is not only a static parameter, but due to the fluctuation-dissipation theorem of the statistical physics it allows to characterize the volume fluctuations and consequently the dynamics of the protein. On the other hand high pressure (usually 5-10 kbar) can unfold proteins, causing the loss of secondary structure. Unlike temperature unfolding, pressure unfolding is usually reversible, therefore refolding of the pressure unfolded proteins can provide information about the refolding pattern, and the folding intermediates on this way. Pressures up to 2 kbar are able to disturb the inter-protein interactions, dissociating oligomers and aggregates. Aggregates are of great interest, because they were associated recently to several serious so called conformational diseases (Alzheimer, amyloidosis, etc.) In these diseases insoluble aggregates of misfolded proteins accumulate in the tissue, causing serious consequences. Pressure dissociated proteins can be used as model systems for the study of the aggregation process. Pressure unfolded proteins can also sometimes populate unstable intermediate structure. Experiments on pressure refolding of mioglobin, lysozyme will be presented and experimental evidence on formation of aggregation prone intermediates on the refolding pathway will be presented.
Email: smeller@puskin.sote.hu
Address: Department of Biophysics, Semmelweis University Budapest, Puskin u. 9. PF 263, H-1444 Budapest, Hungary