Oxidative modification of a proline-rich gliadin peptide

Huang, Xin; Kanerva, Päivi; Salovaara, Hannu; Loponen, Jussi; Sontag‐Strohm, Tuula

doi:10.1016/j.foodchem.2013.05.066

Cited by 11 publications

(5 citation statements)

References 24 publications

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“…As a result, some gliadins/glutelins are not in their native form. To solve this problem, the use of reducing agents, acids, or enzymes is necessary to disrupt the disulfide bonds before their solubilization in alcohol solutions during the extraction procedure [31][32][33][34].…”

Section: Introductionmentioning

confidence: 99%

Rapid, Effective, and Versatile Extraction of Gluten in Food with Application on Different Immunological Methods

Segura

Díaz

Ruiz-Carnicer

et al. 2021

Foods

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One of the main concerns in gluten analysis is to achieve efficient extraction of gluten proteins. Conventional ethanol-based extraction solutions are inefficient and, because of this, it is necessary to use reducing agents or acids for proper solubilization. The extraction recommended by CODEX Standard 118-1979 (revised 2008) utilizes Cocktail solution (patent WO 02/092633 A1). However, it is harmful with a disgusting odor and is not compatible with some immunological techniques. Here, the versatility and extraction capacity of a new Universal Gluten Extraction Solution (UGES) (patent ES 2 392 412 A1) were evaluated using different methodological conditions, food matrices, and various immunological methods. UGES includes safer compounds for both the user and the environment, and it displayed similar extraction efficiency to that of the extraction method recommended for sandwich enzyme-linked immunosorbent assay (ELISA). The extraction time was significantly reduced from 100 to 40 min, depending on the type of the sample. Furthermore, unlike the currently used solution, UGES is compatible with competitive ELISA.

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Section: Introductionmentioning

confidence: 99%

Rapid, Effective, and Versatile Extraction of Gluten in Food with Application on Different Immunological Methods

Segura

Díaz

Ruiz-Carnicer

et al. 2021

Foods

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“…Proteolytic enzymes, such as proteases from seed germination (Loponen, Kanerva, Zhang, Sontag-Strohm, Salovaara & Gänzle, 2009) and proline-endopeptidase (Luoto et al, 2012) may be used for prolamin degradation. We have previously demonstrated that metal-catalyzed oxidation degraded a model celiac peptide 33-mer (Huang, Kanerva, Salovaara, Loponen & Sontag-Strohm, 2013) and C-hordein (Huang, Kanerva, Salovaara & Sontag-Strohm, 2016), as shown by substantial reductions in the immunoreactivity of both substrates in R5-based enzyme-linked immunosorbent assay (ELISA). Protein degradation and aggregation both occurred during oxidation, and oxidation of proline residues could partially explain this phenomenon.…”

Section: Introductionmentioning

confidence: 99%

Oxidation of proline decreases immunoreactivity and alters structure of barley prolamin

et al. 2017

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Elimination of celiac-toxic prolamin peptides and proteins is essential for Triticeae products to be gluten-free. Instead of enzymatic hydrolysis, in this study we investigated metal-catalyzed oxidation of two model peptides, QQPFP, and PQPQLPY, together with a hordein isolate from barley (Hordeum vulgare L.). We established a multiple reaction monitoring (MRM) LC-MS method to detect and quantify proline oxidation fragments. In addition to fragmentation, aggregation and side chain modifications were identified, including free thiol loss, carbonyl formation, and dityrosine formation. The immunoreactivity of the oxidized hordein isolate was considerably decreased in all metal-catalyzed oxidation systems. Cleavage of peptides or protein fragments at the numerous proline residues partially accounts for the decrease. Metal-catalyzed oxidation can thus be used in the modification and elimination of celiac-toxic peptides and proteins.

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“…In aquatic systems, indirect photooxidation by singlet oxygen can also contribute to oxidative damage of proteins . Exoenzyme oxidation in soils can occur through interactions with reactive oxygen species derived from Fenton type reactions of transition metals or peroxidase enzymes with H 2 O 2 produced by soil microorganisms, − but may also result from contact with soil minerals. However, while the pedogenic oxides of manganese are known for their oxidative power toward organic compounds, − reports on the effects of manganese oxide on proteins are limited to a report of apparent oxidative degradation of a prion protein in the presence of birnessite …”

Section: Introductionmentioning

confidence: 99%

Abiotic Protein Fragmentation by Manganese Oxide: Implications for a Mechanism to Supply Soil Biota with Oligopeptides

Reardon

Chacon

Walter

et al. 2016

Environ. Sci. Technol.

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The ability of plants and microorganisms to take up organic nitrogen in the form of free amino acids and oligopeptides has received increasing attention over the last two decades, yet the mechanisms for the formation of such compounds in soil environments remain poorly understood. We used Nuclear Magnetic Resonance (NMR) and Electron Paramagnetic Resonance (EPR) spectroscopies to distinguish the reaction of a model protein with a pedogenic oxide (Birnessite, MnO2) from its response to a phyllosilicate (Kaolinite). Our data demonstrate that birnessite fragments the model protein while kaolinite does not, resulting in soluble peptides that would be available to soil biota and confirming the existence of an abiotic pathway for the formation of organic nitrogen compounds for direct uptake by plants and microorganisms. The absence of reduced Mn(II) in the solution suggests that birnessite acts as a catalyst rather than an oxidant in this reaction. NMR and EPR spectroscopies are shown to be valuable tools to observe these reactions and capture the extent of protein transformation together with the extent of mineral response.

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Oxidative modification of a proline-rich gliadin peptide

Cited by 11 publications

References 24 publications

Rapid, Effective, and Versatile Extraction of Gluten in Food with Application on Different Immunological Methods

Rapid, Effective, and Versatile Extraction of Gluten in Food with Application on Different Immunological Methods

Oxidation of proline decreases immunoreactivity and alters structure of barley prolamin

Abiotic Protein Fragmentation by Manganese Oxide: Implications for a Mechanism to Supply Soil Biota with Oligopeptides

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