Disentangling Volumetric and Hydrational Properties of Proteins

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• 作者：Vladimir P. Voloshin ; Nikolai N. Medvedev ; Nikolai Smolin ; Alfons Geiger ; Roland Winter
• 刊名：Journal of Physical Chemistry B
• 出版年：2015
• 出版时间：February 5, 2015
• 年：2015
• 卷：119
• 期：5
• 页码：1881-1890
• 全文大小：612K
• ISSN：1520-5207

文摘

We used molecular dynamics simulations of a typical monomeric protein, SNase, in combination with Voronoi鈥揇elaunay tessellation to study and analyze the temperature dependence of the apparent volume, V_app, of the solute. We show that the void volume, V_B, created in the boundary region between solute and solvent, determines the temperature dependence of V_app to a major extent. The less pronounced but still significant temperature dependence of the molecular volume of the solute, V_M, is essentially the result of the expansivity of its internal voids, as the van der Waals contribution to V_M is practically independent of temperature. Results for polypeptides of different chemical nature feature a similar temperature behavior, suggesting that the boundary/hydration contribution seems to be a universal part of the temperature dependence of V_app. The results presented here shine new light on the discussion surrounding the physical basis for understanding and decomposing the volumetric properties of proteins and biomolecules in general.