The seed proteins were extracted from 10 mg of the dried,
ground soybean with 200 lL 0.03 M Tris–HCl, pH 8.0, containing
10 mmol L1 dithiothreitol (DTT). The 11S and 7S globulins and
their subunits and polypeptides were separated using 14% sodium
dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE)
under the conditions previously reported (Yang & James, 2013).
The gels were stained overnight with Coomassie brilliant blue
R250. After destaining, the gels were scanned and analysed using
Quantity One software version 4.2.1 (BioRad Australia).
Molecular weight markers (PageRuler Prestained Protein Ladder,
Fermentas) covering 10–170 kDa were used and bands representing
7S and 11S globulin subunits and polypeptides were identified
by their relative mobility against the protein ladder and published
data.