SOLUBILIZATION OF GLUTENIN IN UREA SDS SOLUTIONS AT ELEVATED-TEMPERATURE

Glutenin preparations from glutens of four wheat cultivars of diverse breadmaking potential were tested for protein solubility in 6 M urea/6% (w/v) SDS solution at 50°C. Essentially all the protein from the glutenin preparations was dissolved by dispersing 12 mg of the glutenin preparation in 5 ml of the solvent and incubating for 24 h. The rate of solubilization was indirectly related to the ‘dough strength’ of the wheat cultivar. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDSPAGE) results showed that, for three of the wheat cultivars, the high molecular weight (HMW) subunit compositions of the reduced solubilized glutenin preparations were the same as those of the respective flours. For the cultivar Katepwa, subunits 9 and 10 were not resolved in the pattern of the solubilized glutenin. No HMW subunits were observed in the SDS-PAGE pattern for the solubilized but unreduced glutenin. The solubilization procedure may be useful for further studies on characterization of unreduced glutenin of different wheat cultivars in the context of characterizing the structure-functionality relationships of this protein in breadmaking. © 1992, Academic Press Limited. All rights reserved.