Electrophoretic characterisation of fractions collected from gluten protein extracts subjected to size-exclusion high-performance liquid chromatography

Abstract

The electrophoretic analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE; reduced and unreduced) of fractions, collected from a size exclusion-high performance liquid chromatography (SE-HPLC) separation of gluten proteins using a column with pore size of around 400A, showed clear resolution for the seven elution ranges studied in two Australian bread wheat lines. Polymeric proteins - high molecular weight (HMW) glutenin subunits, low molecular weight (LMW) glutenin subunits, HMW albumins and some modified omega-gliadins - appeared exclusively in the region within the first peak of the chromatogram (fractions 1 to 5), the limit being a region that resolved as a small peak before the large peak of gliadins and where some omega-gliadins eluted. A larger proportion of HMW glutenin subunits and B subunits contributed to polymer formation of higher molecular weight. The polymer size decreased as the proportion of the other protein components increased.