Cereal Chem 66:121-127   |  VIEW ARTICLE

Rapid Purification of Wheat Glutenin for Reversed-Phase High-Performance Liquid Chromatography: Comparison of Dimethyl Sulfoxide with Traditional Solvents.

T. Burnouf and J. A. Bietz. Copyright 1989 by the American Association of Cereal Chemists, Inc. 

Nondefatted and defatted wheat flours were extracted with various solvents to develop a rapid procedure to isolate glutenin for reversed-phase high-performance liquid chromatography (RP-HPLC). Solvents containing 70% ethanol, 60% acetonitrile, 2M dimethylformamide, urea, or combinations of 70% ethanol with acetic acid and beta-mercaptoethanol did not extract all albumins, globulins, and/or gliadins. Some of these proteins may co-elute with glutenin subunits upon RP-HPLC. However, acidic solvents, such as 0.7% acetic acid and aluminum lactate-lactic acid buffer, pH 3.1, efficiently extracted soluble proteins and gliadin so that remaining proteins gave RP-HPLC patterns like glutenin purified by established procedures. Glutenin could be most conveniently isolated, however, by extracting nonglutenin proteins with greater than 90% (v/v) dimethyl sulfoxide, followed by washing the pellet with 70% ethanol. Glutenin remaining in the residue was readily soluble after reduction and pyridylethylation, and could be analyzed by RP-HPLC. Dimethyl sulfoxide extraction also largely freed glutenin of starch, thus favoring sample stability, RP-HPLC resolution, and long column lifetime. Many samples can be processed easily by this method. The procedure should help breeders and geneticists select for specific glutenin compositions that relate to quality.