Cereal Chem 38:256 - 271.  |  VIEW ARTICLE

Proteins of Wheat and Flour. Extraction, Fractionation, and Chromatography of the Buffer-Soluble Proteins of Flour.

J. H. Coates and D. H. Simmonds. Copyright 1961 by the American Association of Cereal Chemists, Inc. 

Six major protein fractions were identified following chromatography on DEAE-cellulose of the proteins extracted by 0.01M sodium pyrophosphate (at pH 7) from each of two flour samples differing widely in protein content and baking performance. The two flours appeared to differ in the relative amounts of certain of the components present. Two of the fractions were resolved further by rechromatography and by electrophoresis, giving a total of ten components so far recognized in these extracts. One fraction (peak A), containing both protein and carbohydrate, passed unretarded through the DEAE-cellulose column. On hydrolysis, the carbohydrate component of peak A yielded arabinose and xylose, together with lesser amounts of galactose. Electrophoresis and further chromatography of peak A on carboxymethyl-cellulose (CM-cellulose) demonstrated it to be heterogeneous and to consist of at least three components. Peaks D, E, and F were eluted from the DEAE-cellulose column in the presence of increasing concentrations of sodium chloride. Electrophoresis experiments indicated the presence of at least five components in this group of proteins with the following approximate mobility values: A, 0-3 x 10[-6]; 19-22 x 10[-6]; E, 26-27 x 10[-6]; F, 43-50 x 10[-6] cm[2] sec-1 volt-1. Peaks D, E, and F were re-chromatographed on DEAE-cellulose to yield single symmetrical peaks. Components J and K were eluted by 0.05N acetic acid and 0.1N sodium hydroxide, respectively. Peaks D and E, F and K have a lower amide and glutamic acid content than peak A and are higher in arginine, aspartic acid, glycine, leucine, and tyrosine.