Lysozyme in water-acetonitrile mixtures: Preferential solvation at the inner edge of excess hydration

• DOI: 10.1063/1.4984116
• Publication Date: 2017-06-01T15:58:18Z
• Authors: Vladimir A. Sirotkin; Alexandra A. Kuch...
• Keywords: Solvation shell; Water activity

Preferential solvation/hydration is an effective way for regulating the mechanism of protein destabilization/stabilization. Organic solvent/water sorption and residual enzyme activity measurements were performed to monitor preferential hen egg-white lysozyme at high low water content in acetonitrile 25 °C. The obtained results show that destabilization/stabilization depends essentially on initial hydration level acetonitrile. There are three composition regimes dried lysozyme. At content, has a higher affinity than values close 100%. intermediate dehydrated water. A minimum curve was observed this concentration range. lowest organic solvent molecules preferentially excluded from lysozyme, resulting hydration. catalytic ∼80%, compared with after incubation pure Two distinct schemes operative hydrated hydrated. However, contrast protein, initially increased parameters. binding detected. No water-poor Our data clearly macromolecules one key factors govern stability protein-water-organic systems.