Physicochemical characterization of hepatic glucocorticoid receptors from pre- and post-weaned mice

The physicochemical parameters viz., molecular weight, stokes radius and ionic state of hepatic glucocorticoid receptors from pre-(10-day) and post-(60-day) weaned mice were studied. Gel permeation studies of the crude receptors showed a molecular mass of approximately 290 kDa for the unactivated receptors from both the age groups while the thermally activated receptors showed a molecular mass of approximately 90 kDa. The stokes radii were approximately 5.8 and 3.6 for the unactivated and activated receptors, respectively from both the age groups studied. Elution of the bound glucocorticoid receptors from anion-exchanger did not reveal any charge difference in the two age groups; the unactivated receptors eluted at approximately 250 mM KCl whereas the activated receptors eluted at approximately 100 mM KCl. Salt extraction of thermally activated nuclear bound receptors and immunological studies on the unactivated receptors revealed no age-related variation in the two groups of mice. Our findings confirm that the physicochemical properties of hepatic glucocorticoid receptors remain unchanged at these developmental stages of mice.