The spectral behaviour of a protein and its hydration water has been investigated through neutron scattering. The availability of both hydrogenated and perdeuterated samples of maltose-binding protein (MBP) allowed us to directly measure with great accuracy the signal from the protein and the hydration water alone. Both the spectra of the MBP and its hydration water show two distinct relaxation...

Hydration and preferential hydration of macromolecules are two distinct properties of their multicomponent aqueous solutions. We have experimentally investigated ternary diffusion in a macromolecule-osmolyte-water system in order to characterize and compare these two independent quantities and to experimentally establish their role on the phenomenon of coupled diffusion. Specifically, we report...

Using microcalorimetry, we follow changes in the association free energy of beta-cyclodextrin (CD) with the hydrophobic part of adamantane carboxylate (AD) due to added salt or polar (net-neutral) solutes that are excluded from the molecular interacting surfaces. Changes in binding constants with solution osmotic pressure (water activity) translate into changes in the preferential hydration upo...

Nanometer-Scale Phase Separation and Preferential Solvation in THF Water Mixtures: Ultrafast Electron Hydration and Recombination Dynamics Following CTTS Excitation of I Arthur E. Bragg,* Godwin U. Kanu, and Benjamin J. Schwartz* Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218-2680, United States Department of Chemistry and Biochemistry, University of California...

How do we estimate, from thermodynamic measurements, the number of water molecules adsorbed or released from biomolecules as a result of a biochemical process such as binding and allosteric effects? Volumetric and osmotic stress analyses are established methods for estimating water numbers; however, these techniques often yield conflicting results. In contrast, Kirkwood-Buff theory offers a nov...

We study the effect of the organic co-solute trimethylamine N-oxide (TMAO) on the volume phase transition of microgel particles made from poly(N-isopropylacrylamide) (PNIPAM) using dynamic light scattering (DLS) and all-atom molecular dynamics (MD) simulations. The DLS measurements reveal a continuous TMAO-induced shrinking process from a coil to a globular state of PNIPAM microgel particles. A...