Cereal Chem 43:495 - 516.  |  VIEW ARTICLE

The Extraction and Ion-Exchange Chromatography of Buffer-Soluble and Gluten Proteins of Wheat Flour.

J. W. Clayton. Copyright 1966 by the American Association of Cereal Chemists, Inc. 

Methods for the extraction and chromatographic separation of wheat flour proteins have been developed as part of a comprehensive study of cereal proteins. Proteins were extracted by treating flour successively with four portions of pyrophosphate-ethylenediaminetetraacetate buffer (at pH 7.0) followed by four portions of 0.01N formic acid. This extraction procedure solubilizes 95% of the total flour nitrogen. The buffer extracts were fractionated on carboxymethyl (CM) cellulose at pH 5.5. Much of the buffer-soluble protein is not adsorbed on CM cellulose under these conditions. This unadsorbed protein was fractionated on diethylaminoethyl (DEAE) cellulose at pH 7.0. The gluten proteins were fractionated on CM cellulose at pH 4.0 with eluant solutions which contained the protein dispersant dimethylformamide. Six varieties of vulgare wheat and two varieties of durum wheat have been studied with these techniques. The vulgare wheat protein chromatograms are characterized by a marked intervarietal similarity, although there are intervarietal differences in the total amounts of buffer-soluble and gluten proteins. On the other hand, one buffer-soluble protein which is prominent in vulgare wheats was not found in durum wheats.