Preferential solvation of lysozyme in water/ethanol mixtures.
We provide a quantitative description of the solvation properties of lysozyme in water/ethanol mixtures, which has been obtained by a simultaneous analysis of small-angle neutron scattering and differential scanning calorimetry experiments. All data sets were analyzed by an original method, which integrates the exchange equilibrium model between water and ethanol molecules at the protein surface and activity coefficients data of water/ethanol binary mixtures. As a result, the preferential binding of ethanol molecules at the protein surface was obtained for both native and thermal unfolded protein states. Excess solvation numbers reveal a critical point at ethanol molar fraction ≈0.06, corresponding to the triggering of the hydrophobic clustering of alcohol molecules detected in water/ethanol binary mixtures.
Department of Life and Environment Sciences, Marche Polytechnic University and CNISM, I-60131 Ancona, Italy.
Maria Grazia
MG
Ortore
Paolo
P
Mariani
Flavio
F
Carsughi
Stefania
S
Cinelli
Giuseppe
G
Onori
José
J
Teixeira
Francesco
F
Spinozzi
D000818:Animals; D002152:Calorimetry, Differential Scanning; D002645:Chickens; D000431:Ethanol / Q000737:chemistry; D009113:Muramidase / Q000737:chemistry*; D012995:Solubility; D014867:Water / Q000737:chemistry
D014867:Water; D000431:Ethanol; C421864:hen egg lysozyme; D009113:Muramidase