Preparation and Characterization of α-Gliadin

Bernardin, John E.; Kasarda, Donald D.; Mecham, Dale K.

doi:10.1016/s0021-9258(18)96293-9

Cited by 79 publications

(6 citation statements)

References 18 publications

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“…Sample Preparation. The sample of A-gliadin was prepared according to the method of Bernardin et al (5). The ω-gliadin sample, prepared according to the method of Kasarda et al (12), was a mixture of ω-1 and ω-2 components of the 1D group.…”

Section: Methodsmentioning

confidence: 99%

“…The C-terminal domain includes all six cysteine residues that form three intramolecular disulfide bonds, along with a second short polyglutamine sequence. Kasarda and co-workers (5)(6)(7)(8)(9)(10) have extensively studied a purified fraction of R-gliadins known as A-gliadin that can form microfibrillar structures with diameters of about 0.8 nm and 300-400 nm in length depending on pH (5 or higher) and ionic strength (5 mM KCl); the microfibrils are similar in appearance to amyloid fibrils, but the proteins do not undergo major conformational changes during aggregation. These microfibrils can be disaggregated into monomers and reaggregated by varying the pH or ionic strength (6).…”

mentioning

confidence: 99%

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New Insight into the Solution Structures of Wheat Gluten Proteins from Raman Optical Activity

et al. 2003

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Vibrational Raman optical activity (ROA) spectra of the wheat proteins alpha-gliadin (A-gliadin), omega-gliadin, and a 30 kDa peptide called T-A-1 from the high molecular weight glutenin subunit (HMW-GS) Dx5 were measured to obtain new information about their solution structures. The spectral data show that, under the conditions investigated, A-gliadin contains a considerable amount of hydrated alpha-helix, most of which probably lies within a relatively structured C-terminal domain. Smaller quantities of beta-structure and poly(l-proline) II (PPII) helix were also identified. Addition of methanol was found to increase the alpha-helix content at the expense of some of the beta and PPII structure. In comparison, omega-gliadin and the T-A-1 peptide were found to consist of large amounts of well-defined PPII structure with some turns but no alpha-helix. The results for the T-A-1 peptide are in agreement with a model in which HMW-GS are extended but not highly rigid. Application of a pattern recognition technique, based on principal component analysis (PCA), to the ROA spectra reinforces these conclusions.

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Section: Methodsmentioning

confidence: 99%

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confidence: 99%

New Insight into the Solution Structures of Wheat Gluten Proteins from Raman Optical Activity

et al. 2003

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“…It has been shown that noncovalent intermolecular interactions exert a dominant effect on the viscoelastic properties of hydrated gliadins . It has also been demonstrated that gliadins weaken the strength of dough and soften gluten. − Previous studies on the sulfur-rich α- and γ-gliadins in dilute acids or ethanol/water solutions have indicated that the C-terminal domains of those gliadins are rich in α-helical content and adopt a compact globular structure stabilized by disulfide bonds. ,− The N-terminal repetitive domains are nonglobular and contain elements of a poly- l -proline II structure and β-reverse turns. − Because gliadins are known to have poor water solubility, analyses such as electrophoresis and viscoelastic measurements have been performed on gliadins that were extracted with an ethanol/water solution or dilute acetic acid. , However, it is not known if gliadins in alcohols or acids show the same behavior as those in water. In addition, gliadins exist as a hydrated solid in food.…”

Section: Introductionmentioning

confidence: 99%

Molecular Assembly of Wheat Gliadins into Nanostructures: A Small-Angle X-ray Scattering Study of Gliadins in Distilled Water over a Wide Concentration Range

Sato

Matsumiya

Higashino

et al. 2015

J. Agric. Food Chem.

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Gliadin, one of the major proteins together with glutenin composing gluten, affects the physical properties of wheat flour dough. In this study, nanoscale structures of hydrated gliadins extracted into distilled water were investigated primarily by small-angle X-ray scattering (SAXS) over a wide range of concentrations. Gliadins are soluble in distilled water below 10 wt %. Guinier analyses of SAXS profiles indicate that gliadins are present as monomers together with small amounts of dimers and oligomers in a very dilute solution. The SAXS profiles also indicate that interparticle interference appears above 0.5 wt % because of electrostatic repulsion among gliadin assemblies. Above 15 wt %, gliadins form gel-like hydrated solids. At greater concentrations, a steep upturn appears in the low-q region owing to the formation of large aggregates, and a broad shoulder appears in the middle-q region showing density fluctuation inside. This study demonstrates that SAXS can effectively disclose the nanostructure of hydrated gliadin assemblies.

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“…Since this peak occurred in both foams and films it was not related to the cell structure itself but must have been associated with the protein matrix. The fact that the correlation peak was small, or absent, in the glutenin foams, seems to indicate that the peak originated from the protein structure associated with gliadin and was probably connected to the fibrillated/aggregated ordered structures of gliadins reported by Kasarda et al 42 and by Bernardin et al 43 WAXS profiles of all the foams are presented in Fig. 11.…”

Section: Saxs and Waxsmentioning

confidence: 78%