Jump to Main Content
Differences in amino acid sequences of gliadin and glutenin
- Bietz, J.A., Rothfus, J.A.
- Cereal chemistry 1971 v.48 no.6 pp. 677
- wheat, winter wheat, hard red winter wheat, glutenins, gliadin, amino acid sequences, peptides, proteolysis, enzymatic hydrolysis, pepsin, amino acid composition, acid treatment
- Gliadin and glutenin were examined to identify peptides that differentiate the proteins. Pronase-resistant fragments from gliadin and glutenin have average mol. wt. of 460 and 640, respectively, and in acid are readily converted to pyroglutamic acid (PGA) peptides. PGA-peptides isolated from pepsin-hydrolysed Pronase digests contained glutamine (Gln) or glutamic acid; proline, serine, and glycine were other common residues. Several peptides were common to digests of both proteins; but most were unique, demonstrating sequence differences between gliadin and glutenin. Yield data suggested that most unique peptides were from a single protein or only a few different ones. Glycine occurs more frequently in the PGA-peptides from glutenin; and proline, in those from gliadin. That Gln is also positioned differently in the 2 proteins was evidence by the enzymatic release of more PGA from glutenin than from gliadin and more PGA-Gln and PGA-Gln-Gln from gliadin than from glutenin.