title: Comparison of repetitive sequences derived from high molecular weight subunits of wheat glutenin, an elastomeric plant protein.
abstract: A strategy has been developed to create repetitive peptides incorporating substitutions in the PGQGQQGYYPTSLQQ consensus repeat sequence of high molecular weight subunits in order to investigate natural sequence variations in elastomeric proteins of wheat gluten. After introduction of glutamic and aspartic acid residues, the peptide behaved similarly to the unmodified form at low pH, but became readily water soluble at pH > 6. Substitution of Gln for Leu at position 13 resulted in only small changes to the secondary structure of the water-insoluble peptides, as did Tyr8His and Thr11Ala. The effects of proline substitutions depended on their location: Leu13Pro substitution had little effect on solubility and structure, but Gln6Pro substitution resulted in dramatic changes. Peptides with two Gln6Pro substitutions had similar properties to the water-insoluble parental peptide, but those with 6 or 10 substitutions were readily soluble. The results indicated that specific sequences influence noncovalent intermolecular interactions in wheat gluten proteins.
authors.affiliation: Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, UK. wellner@bbsrc.ac.uk
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Wellner
authors.forename: Justin T
authors.initials: JT
authors.lastname: Marsh
authors.forename: Andrew W J
authors.initials: AW
authors.lastname: Savage
authors.forename: Nigel G
authors.initials: NG
authors.lastname: Halford
authors.forename: Peter R
authors.initials: PR
authors.lastname: Shewry
authors.forename: E N
authors.initials: EN
authors.lastname: Clare Mills
authors.forename: Peter S
authors.initials: PS
authors.lastname: Belton
mesh_terms: D000595:Amino Acid Sequence; D005983:Glutens / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009154:Mutation; D010446:Peptide Fragments / Q000737:chemistry* / Q000235:genetics; D014908:Triticum / Q000737:chemistry*
chemical_list: D010446:Peptide Fragments; D005983:Glutens; C037302:glutenin