title: Charge-based characterisation of high-molecular-weight glutenin subunits from common wheat by capillary isoelectric focusing.
abstract: In this study, the capillary isoelectric focusing (CIEF) method for the separation and charge characterisation of the heterogeneity of high molecular-weight-glutenin subunits (HMW-GS) in common wheat (Triticum aestivum L.) using linear polyacrylamide (LPA) and polyvinyl alcohol (PVA) coated capillaries was developed. Particularly good repeatability and well-resolved charge isoform profiles were obtained by introducing a mixture of carrier ampholytes (pH 3-10 and pH 5-8), a high concentration of urea (6M) and SB3-12 as detergent in a sample solution during separation in a PVA-coated capillary. One major and one or two minor isoforms were observed for the individual HMW-GS. These isoforms were satisfactorily separated using a pH gradient into two groups: y-type isoforms and x-type isoforms encoded by the Glu-B1 locus with shorter migration times and remaining x-type isoforms with longer times. The method produced from eight to twelve isoforms of wheat HMW-GS with pI points in the range of 4.72-6.98. Generally, the minor isoforms were more acidic compared with the major isoform. The y-type subunits had an approximately neutral character (pI 6.70-6.98); however, x-types showed a weakly acidic character (pI 4.72-5.23), with the exception of subunits encoded by the Glu-B1 locus. The isoelectric point peak profiles were compared with capillary zone electrophoresis (CZE) electropherograms. Generally, the number of detected isoforms for the particular HMW-GS detected using both methods were similar.
authors.affiliation: Institute of Plant Genetics of the Polish Academy of Science, Strzeszyńska Str. 34, 60-479 Poznań, Poland. Electronic address: bsal@igr.poznan.pl.
authors.forename: Bolesław P
authors.initials: BP
authors.lastname: Salmanowicz
authors.affiliation: Institute of Plant Genetics of the Polish Academy of Science, Strzeszyńska Str. 34, 60-479 Poznań, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Langner
authors.affiliation: Institute of Plant Genetics of the Polish Academy of Science, Strzeszyńska Str. 34, 60-479 Poznań, Poland.
authors.forename: Sławomir
authors.initials: S
authors.lastname: Franaszek
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D001939:Bread; D019075:Electrophoresis, Capillary / Q000379:methods*; D004591:Electrophoresis, Polyacrylamide Gel; D005433:Flour; D005504:Food Analysis / Q000379:methods; D005983:Glutens / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007525:Isoelectric Focusing / Q000379:methods*; D008970:Molecular Weight; D011142:Polyvinyl Alcohol / Q000737:chemistry; D020033:Protein Isoforms / Q000737:chemistry; D014908:Triticum / Q000737:chemistry*; D014508:Urea / Q000737:chemistry; D000099166:Polyacrylamides
chemical_list: D000180:Acrylic Resins; D005983:Glutens; D011142:Polyvinyl Alcohol; D020033:Protein Isoforms; D014508:Urea; D000099166:Polyacrylamides; C037302:glutenin
keywords: Capillary coatings; Capillary electrophoresis; HMW glutenin subunits; Isoelectric point; Wheat