Cereal Chem 43:14 - 27.  |  VIEW ARTICLE

Isolation and Characterization of a High-Molecular-Weight Protein from Wheat Gliadin.

A. C. Beckwith, H. C. Nielsen, J. S. Wall, and F. R. Huebner. Copyright 1966 by the American Association of Cereal Chemists, Inc. 

Gliadin, the alcohol-soluble protein of wheat gluten, was found to contain a small amount of a high- molecular-weight (MW) fraction when analyzed by gel filtration on columns of Sephadex G-100. The chromatograms were quite similar when either 0.01M or 0.1M acetic acid was used as eluting solvent. The resolution obtained with 3M urea-0.01N acetic acid as eluting solvent, was not so good as with 0.1M acetic acid. Increasing the temperature from 25 to 40 C. had no effect upon the resolution pattern of the fractions. The heaviest fraction had a MW of about 100,000, whereas the lightest had a MW of about 30,000 in a strongly deaggregating solvent system. Moving-boundary and starch-gel-electrophoretic patterns of the heaviest fraction as well as amino acid composition, solubility, viscosity, sedimentation, and diffusion constants were suggestive of a low-MW glutenin. The moving-boundary and starch-gel-electrophoretic patterns of the lightest contained the major gliadin components - alpha, beta, and gamma. Alpha-gliadin obtained by chromatography on carboxymethyl cellulose also contained components similar to the heaviest gliadin fraction obtained by gel filtration on Sephadex G-100.