| Abstract: | Evidence is presented that the high-molecular-weight gluteninprotein subunits of hexaploid wheat can form oligomers whichare detectable by sodium dodecyl sulphate-polyacrylamide gelelectrophoresis. The oligomers appear when trace amounts of2-mercaptoethanol (2-ME) are used in the extracting solvent,although the presence of a small disulphide compound (cystaminedi HC1) was found to enhance their resolution. These oligomersare not present when high levels of 2-ME are used, which indicatesthat disulphide bonds (probably inter-molecular) are essentialto maintain the association of the constituent polypeptides.It was found that (i) the subunits show specificity when theyassociate to form oligomers, for some subunit associations werenot detected amongst the oligomers (ii) the subunits controlledby chromosome ID are extensively involved in oligomer formationand (iii) different combinations of subunits controlled by chromosomeIB apparently differ in their ability to associate with subunitscontrolled by other chromosomes. The role of the oligomers inthe structure of native glutenin is discussed and their possibleinfluence on bread-making quality considered. Key words: Gel electrophoresis, Oligomers of glutenin, Wheat glutenin |
