Abstract
Subcellular localization of β-conglycinin and glycinin in developing soybean cotyledons was examined by sucrose density gradient ultracentrifugation (SDG-UC). Two major bands appeared at densities of 1.05 and 1.15 in the SDG-UC. They were the microbody fraction and rER fraction, respectively, from the distribution of marker enzymes, electron microscopic observation, and the effects of MgCl2 on the profile of SDG-UC. In the soluble and microbody fractions, α and α' subunits of β-conglycinin were major polypeptides. The amounts of β-conglycinin and glycinin associated with rER were roughly equal. β-Conglycinin was found in the soluble and microbody fractions as well as the rER fraction while glycinin was mostly localized in the rER fraction.