Oxidation of proline decreases immunoreactivity and alters structure of barley prolamin

Huang, Xin; Sontag‐Strohm, Tuula; Stoddard, Frederick L.; Kato, Yoji

doi:10.1016/j.foodchem.2016.07.108

Cited by 15 publications

(12 citation statements)

References 35 publications

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“…With the increasing concentration of AAPH, the content of the α‐helix decreased at 0–0.2 mmol/L AAPH and then increased at 0.2–10 mmol/L AAPH, the change in the β‐sheet content was exactly the opposite to that of the α‐helix content, while the β‐turn content and random coil content were increased significantly. Normally, the oxidation of AAPH causes the ordered α‐helix and β‐sheet structure in EYHDL to transform into a disordered random coil and β‐turn structure, and the increased α‐helix content in EYHDL under high‐oxidant conditions was different from that reported in previous related studies (Huang, Sontag‐Strohm, Stoddard, & Kato, ; Wang, He, Gan, & Li, ). Moderate oxidation can induce partial unfolding of the proteins, thereby exposing certain sites that are normally hidden within proteins (Estévez, ) and leading to a reduction in the intramolecular hydrogen bonds.…”

Section: Resultscontrasting

confidence: 58%

“…Normally, the oxidation of AAPH causes the ordered α-helix and β-sheet structure in EYHDL to transform into a disordered random coil and β-turn structure, and the increased α-helix content in EYHDL under high-oxidant conditions was different from that reported in previous related studies (Huang, Sontag-Strohm, Stoddard, & Kato, 2017;Wang, He, Gan, & Li, 2018). Moderate oxidation can induce partial unfolding of the proteins, thereby exposing certain sites that are normally hidden within proteins (Estévez, 2011) and leading to a reduction in the intramolecular hydrogen bonds.…”

Section: Changes In the Secondary/tertiary Structure Of Oxidized Eyhdlmentioning

confidence: 68%

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Variation in the structure and emulsification of egg yolk high‐density lipoprotein by lipid peroxide

Bao

Kang

et al. 2019

J Food Biochem

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To further clarify the effect of the oxidation of egg yolk high‐density lipoprotein (EYHDL) on the protein structure and emulsification, 2,2′‐azobis (2‐methylpropionamidine) dihydrochloride (AAPH) was selected as a representative lipid peroxidation‐derived peroxyl radical. The results of Raman spectroscopy indicated that, with the increase in the concentration of AAPH, the EYHDL carbonyl content increased significantly and the free sulfhydryl content declined sharply. Circular dichroism spectroscopy and intrinsic fluorescence indicated that exposure of EYHDL to AAPH led to destruction of the orderly structure and reduction of the structural stability. The particle size distribution and zeta potential indicated that the peroxyl radical caused molecular aggregation. Moderate oxidizing conditions can enhance the emulsification of EYHDL, and high‐intensity oxidation decreased emulsification. The research results indicated that EYHDL made a significant change in the oxidation system and led to a change in its structure and emulsification, providing a theoretical basis to clarify the EYHDL oxidation mechanism. Practical applications Egg yolk powder is prone to emulsification degradation during storage. The emulsification of egg yolk powder is mainly derived from high‐density lipoprotein in egg yolk. Moreover, egg yolk powder contains a large amount of lipids, and, during the processing and storage of egg yolk powder, many lipid peroxyl radicals are inevitably generated. Therefore, it is desired to combine the lipid peroxyl radicals generated during the storage of egg yolk powder with the decrease in emulsifiability. In this paper, we first investigated the effects of peroxyl radicals on the structure and emulsifying properties of high‐density lipoproteins and provided a theoretical basis to solve the problem that the emulsifiability of egg yolk powder is significantly reduced during storage.

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Section: Resultscontrasting

confidence: 58%

Section: Changes In the Secondary/tertiary Structure Of Oxidized Eyhdlmentioning

confidence: 68%

Variation in the structure and emulsification of egg yolk high‐density lipoprotein by lipid peroxide

Bao

Kang

et al. 2019

J Food Biochem

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“…For biochemical processing, usage of food-grade microbial transglutaminase (mTG) with lysine ethyl ester is able to modify gliadin peptides, which inhibits the ability of gluten to trigger the specific human immune response in vitro [4]. Huang et al (2017) found a metal-catalyzed oxidation system can cause the modification and elimination of hordein, leading to the decrease of immunoreactivity of hordein [5].…”

Section: Introductionmentioning

confidence: 99%

Effects of Cold Jet Atmospheric Pressure Plasma on the Structural Characteristics and Immunoreactivity of Celiac-Toxic Peptides and Wheat Storage Proteins

Sun

Xie

Zhang

et al. 2020

IJMS

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The present research reported the effects of structural properties and immunoreactivity of celiac-toxic peptides and wheat storage proteins modified by cold jet atmospheric pressure (CJAP) plasma. It could generate numerous high-energy excited atoms, photons, electrons, and reactive oxygen and nitrogen species, including O3, H2O2, •OH, NO2− and NO3− etc., to modify two model peptides and wheat storage proteins. The Orbitrap HR-LC-MS/MS was utilized to identify and quantify CJAP plasma-modified model peptide products. Backbone cleavage of QQPFP and PQPQLPY at specific proline and glutamine residues, accompanied by hydroxylation at the aromatic ring of phenylalanine and tyrosine residues, contributed to the reduction and modification of celiac-toxic peptides. Apart from fragmentation, oxidation, and agglomeration states were evaluated, including carbonyl formation and the decline of γ-gliadin. The immunoreactivity of gliadin extract declined over time, demonstrating a significant decrease by 51.95% after 60 min of CJAP plasma treatment in vitro. The CJAP plasma could initiate depolymerization of gluten polymer, thereby reducing the amounts of large-sized polymers. In conclusion, CJAP plasma could be employed as a potential technique in the modification and reduction of celiac-toxic peptides and wheat storage proteins.

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“…In model systems, peptides QQPFP and PQPQLPY derived from barley hordein were oxidized at different positions in the presence of hydroxyl radicals and the authors concluded that this might explain the reduce immunoreactivity of the oxidized hordein because QQPFP and PQPQLPY are core parts of T‐cell stimulating peptides (Huang, Sontag‐Strohm, Stoddard, & Kato, ). Di‐tyrosine was formed through oxidation of peptide PQPQLPY with hydroxyl radicals but not with ascorbic acid and in addition, the degradation of proline was more pronounced in QQPFP than in PQPQLPY although, the later has more proline residues (Huang et al, ). This emphasizes the importance of the structure (i.e., sequence) on the reactivity of food peptides with HO• radicals as in this case proline at the C‐terminal is more readily attacked by this reactive species.…”

Section: Reaction Of Peptide With Hydroxyl Radicalsmentioning

confidence: 99%

Reactivity of peptides within the food matrix

Kamdem

Tsopmo

2017

J Food Biochem

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Numerous biological activities have been reported for peptides or peptide-rich fractions from hydrolyzed food proteins. Some of the properties of peptides include antioxidant, antimicrobial, anti-inflammation, antihypertensive, and immune system modulation. To evaluate the efficacy of peptides in vivo, foods have been used as carrier vehicles. However, there are many molecules in foods that can react or interact with peptides, thereby reducing the bioavailability or bioactivity of these peptides. The Schiff base reactions of peptides with reducing sugars are well established.Peptides can also react with oxidized lipids or reactive oxygen species. Secondary metabolites such as quinones in foods, can react as well with amine or thiol groups of peptides. All these reactions affect the concentration of peptides. This review summarizes and discusses some of the implication of those reactions on the availability of bioactive peptides within the food matrix.

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Oxidation of proline decreases immunoreactivity and alters structure of barley prolamin

Cited by 15 publications

References 35 publications

Variation in the structure and emulsification of egg yolk high‐density lipoprotein by lipid peroxide

Variation in the structure and emulsification of egg yolk high‐density lipoprotein by lipid peroxide

Effects of Cold Jet Atmospheric Pressure Plasma on the Structural Characteristics and Immunoreactivity of Celiac-Toxic Peptides and Wheat Storage Proteins

Reactivity of peptides within the food matrix

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