Cereal Chem 56:317 - 320.  |  VIEW ARTICLE
Separation of the 13S Globulin in Sesame Seeds into Two Groups of Acidic and Basic Subunits, and Their Physicochemical Properties.

K. Okubo, N. Nishimura, and K. Shibasaki. Copyright 1979 by the American Association of Cereal Chemists, Inc. 

The 13S globulin in sesame seeds was composed of acidic and basic subunits. These subunits were separated into two fractions by column chromatography on DEAE-Sephadex A-50 containing urea and 2- mercaptoethanol-a fraction including the acidic subunts and a second fraction including the basic subunits, whose isoelectric points were pH 5.5-6.5 and 8.5-9.5, respectively, on estimation by gel isoelectric focusing. The molecular weights of the acidic and basic subunits were estimated as 30,500-33,500 and 20,000-24,500 daltons, respectively, by gel filtration and by sodium dodecyl sulfate (SDS) gel electrophoresis. The acidic and basic subunits were suggested to be present in equimolar amounts in the 13S globulin molecule by the densitometric scanning of the SDS gel and the molecular weight consideration. There were significant differences in the amino acid compositions of the acidic and basic subunits as illustrated by lower contents of threonine, serine, valine, methionine, lysine, and aspartic acid, and higher content of glutamic acid in the acidic than in the basic subunits. Glycine in the group of acidic subunits, and glycine and valine in the group of basic subunits, were detected as N-terminal amino acids.