Hydrate Properties and Molecular Mobility in the Protein-Disaccharide Systems at Low Humidity

Abstract

The freeze dried samples of bovine serum albumin (BSA) and BSA—saccharose, BSA—lactose, and BSA—trehalose complexes were studied by the proton NMR relaxation technique in the humidity range from 1 to 20%. The disaccharide molecules were found to assume translational mobility at the humidity higher than 12% per dry weight. It was established that, at the same water content in the samples, saccharose, lactose, and trehalose possess, respectively, high, intermediate, and low mobility. To display water “dissolving” properties in these systems at a humidity higher than 12%, two, three, and four water molecules are required additionally per each sugar molecule for, respectively, saccharose, lactose, and trehalose.