The high molecular weight subunits of wheat glutenin and their role in determining the functional properties of wheat gluten and dough

The HMW subunits of wheat glutenin are present in high M-r, glutenin polyme rs, the amounts and properties of which have major effects on the visco-ela sticity and hence processing properties of doughs. The individual HMW subun its contain an extensive domain of repeated sequences, which appears to for m an unusual spiral supersecondary structure. We propose that the HMW subun its form the "backbone" of the glutenin polymers, stabilized by inter-chain disulphide bonds between cysteine residues present in the non-repetitive N - and C-terminal domains. We also propose that inter-chain hydrogen bonding between the repetitive domains of adjacent subunits may contribute to glut en viscoelasticity, via a "loop and train" mechanism.