Embedding protein in sugar systems of low water content enables one to investigate the protein dynamicstructurefunction in matrixes whose rigidity is modulated by varying the content of residual water. Accordingly, studying thedynamics and structure thermal evolution of a protein in sugar systems of different hydration constitutes a tool for disentanglingsolvent rigidity from temperature effects. Furthermore, studies performed using different sugars may give information on howthe detailed composition of the surrounding solvent affects the internal protein dynamics and structural evolution. In this work,we compare Fourier transform infrared spectroscopy measurements (300–20 K) on MbCO embedded in trehalose, sucrose,maltose, raffinose, and glucose matrixes of different water content. At all the water contents investigated, the protein-solventcoupling was tighter in trehalose than in the other sugars, thus suggesting a molecular basis for the trehalose peculiarity. Theseresults are in line with the observation that protein-matrix phase separation takes place in lysozyme-lactose, whereas it isabsent in lysozyme-trehalose systems; indeed, these behaviors may respectively be due to the lack or presence of suitablewater-mediated hydrogen-bond networks, which match the protein surface to the surroundings. The above processes might beat the basis of pattern recognition in crowded living systems; indeed, hydration shells structural and dynamic matching is firstneeded for successful come together of interacting biomolecules.
|Number of pages||13|
|Publication status||Published - 2006|
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