Interfacial water at protein surfaces: wide-line NMR and DSC characterization of hydration in ubiquitin solutions.

ABSTRACT: Wide-line 1H-NMR and differential scanning calorimetry measurements were done in aqueous solutions and on lyophilized samples of human ubiquitin between -70 degrees C and +45 degrees C. The measured properties (size, thermal evolution, and wide-line NMR spectra) of the protein-water interfacial region are substantially different in the double-distilled and buffered-water solutions of ubiquitin. The characteristic transition in water mobility is identified as the melting of the nonfreezing/hydrate water. The amount of water in the low-temperature mobile fraction is 0.4 g/g protein for the pure water solution. The amount of mobile water is higher and its temperature dependence more pronounced for the buffered solution. The specific heat of the nonfreezing/hydrate water was evaluated using co

SUBMITTER: Tompa K 

PROVIDER: S-EPMC2711274 | biostudies-literature | 2009 Apr

REPOSITORIES: biostudies-literature