Dielectric dispersion measurements of dimeric and monomeric forms of phosphorylase b

Rabbit skeletal muscle phosphorylase b was investigated by the dielectric dispersion method in different media. Comparison of calculated and measured relaxation times revealed the effective molecular diameters to be higher than published earlier. Using an estimated value of 4 A for the thickness of the hydration layer of the protein, a good agreement was obtained between the calculated and measured relaxation times. On the basis of these calculations and measurements the molecular dimensions of hydrate phosphorylase b were taken for 118 X 74 X 63 A. Dispersion measurements suggested that the volume of a subunit was smaller than the half volume of the dimeric form.