Cereal Chem 72:527-532  |  VIEW ARTICLE

Separation and Characterization of Wheat Protein Fractions by High-Performance Capillary Electrophoresis.

G. Lookhart and S. Bean. Copyright 1995 by the American Association of Cereal Chemists, Inc. 

Wheat protein fractions, separated by the Osborne Solvent Fractionation Procedure, were characterized by high-performance capillary electrophoresis (HPCE). Each fraction was separated on a 27-cm fused-glass capillary (20 micrometers, i.d.) using 0.1M phosphate buffer (pH 2.5) containing hydroxypropylmethylcellulose, a polymer additive, at 45 C and 22 kV constant voltage. Albumins and globulins migrated in the first 4 min, whereas gliadins and glutenins migrated after 4 min. Individual alpha, beta, gamma, and omega gliadin proteins, which were collected from reversed-phase high-performance liquid chromatography (RP-HPLC) separations, were also separated by HPCE. Combined results of this study and our previous studies provide a catalog of individual gliadin information from HPCE, HPLC, acid- polyacrylamide gel electrophoresis (A-PAGE) and sodium dodecyl sulfate (SDS)-PAGE, relating class, relative molecular size, hydrophobicity, relative charge, and separation times of each gliadin subclass by HPLC and HPCE. The main advantages of HPCE are: 1) the complementing of other electrophoretic and chromatographic protein separation methods, and 2) safety because no toxic acrylamides and only minute amounts of organic solvents and buffers are used.