An investigation by dielectric methods of hydration in myoglobin solutions

Abstract

The permittivities of three solutions of sperm whale myoglobin of different concentrations were measured in the frequency range 300 to 1300 MHz at 20°C by using a coaxial line technique. These results were combined with those measured previously at frequencies below 10 MHz. Two methods are described for calculating the extent of macromolecular hydration from the data. The more reliable method yields results of approx. 0.25 g of H2O/g of protein, which is in satisfactory agreement with the theoretically calculated value. Agreement with the value found from the rotational motion of the molecule is not so close, which is probably caused by the different meanings that may be ascribed to the term hydration.