**2. Storage proteins**

A combined proteomic approach was employed for the separation, identification, and comparison of two major storage proteins, beta-conglycinin and glycinin, from cultivat‐ ed (*Glycine max*) and wild (*Glycine soja*) soybean seeds. Two-dimensional polyacrylamide gel electrophoresis with three different immobilized pH gradient strips effectively re‐ solved many storage proteins. The pH range 3.0 - 10.0 was good for separating most of the beta-conglycinin subunits while pH ranges 4.0 - 7.0 and 6.0 - 11.0 were satisfactory for separating acidic and basic glycinin polypeptides, respectively. Although the distri‐ bution pattern of the protein spots was in general alike in both genotypes by employ‐ ing pH 3.0 - 10.0, variations in number and intensity of protein spots were better resolved when a combination of pH 4.0 - 7.0 and pH 6.0 - 11.0 was utilized. The total number of storage protein spots detected in wild and cultivated genotypes was approxi‐ mately 44 and 34, respectively [1].

Krishnan et al have developed a fast and simple fractionation technique using 10 mM Ca2+ to precipitate soybean seed storage globulins, glycinin and beta-conglycinin. This method eliminates over 80% of the highly abundant seed proteins from the extract, facilitating detec‐ tion of previously inconspicuous proteins in soybean seed [2].
