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Title: CAPILLARY ELECTROPHORESIS: A STATE-OF-THE-ART TECHNIQUE FOR WHEAT PROTEIN CHARACTERIZATION

Author
item Bietz, Jerold
item Lookhart, George
item BEAN, S - KANSAS STATE UNIV
item SUTTON, KEVIN - NEW ZEALAND INST.CROP RES

Submitted to: Royal Society of Chemistry Meetings
Publication Type: Review Article
Publication Acceptance Date: 8/15/1995
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: We have developed methods that give excellent separations of wheat gluten proteins by capillary electrophoresis(CE). For gliadin, variables examined include protein extractant; buffer type, source, and pH; buffer additives (SDS, acetonitrile, reducing agents, polymeric matrices); capillary length and diameter; voltage; temperature; and injection mode. Best separations were at 22 kV with 0.1M phosphate buffer, pH 2.5, containing a linear hydrophilic polymer, using a 20 cm x 20 micrometer i.d. uncoated silica capillary. Resolution in 10 min is as good as that of reversed-phase high-performance liquid chromatography (RP-HPLC); one real advantage of CE is that it complements RP-HPLC separations, as shown by analyzing isolated RP-HPLC peaks. CE is also the first automated electrophoresis method and gives good quantitative results. Good inter-laboratory reproducibility can be achieved, but buffer composition is critical. CE readily differentiates wheat varieties, including ones closely related. It should be useful for selection during breeding and in genetic studies. Modified ProSort technology [Werner et al, Cereal Chem. 71:397 (1994)] also identified high molecular weight glutenin subunits in several cultivars. Results were similar to those from gel electrophoresis, but some differences in relative mobilities of proteins occurred. CE is rapidly becoming a valuable addition to other analytical tools for wheat protein analysis.