PHYSICO‐CHEMICAL STUDIES ON THE 11S GLOBULIN IN SOYBEAN SEEDS: SIZE AND SHAPE DETERMINATION OF THE MOLECULE

Abstract

The molecular shape of the 11S globulin, the major storage protein of soybean seeds, was estimated to be an oblate ellipsoid with a revolution axial ratio of 8.11-8.38 with or without scarce hydration according to the procedure of Simha and Perrin by measuring the partial specific volume, diffusion coefficient, MW and volume fraction intrinsic viscosity. The length of the major axis of the molecule is 178-180 .ANG. and that of the minor axis 22 .ANG.. The shape factor .beta., and the hydrodynamically effective volume, Ve, of the protein were calculated by the procedure of Scheraga and Mandelkern. The 11S globulin molecule was also an oblate ellipsoid from .beta.. Ve was found to be equal to M.hivin.V/N, the anhydrous volume of proteon. The protein apparently exists in a rigid and nearly anhydrous state in solution.