Clustering and cross-linking of the wheat storage protein α-gliadin: A combined experimental and theoretical approach

Markgren, Joel; Rasheed, Faiza; Hedenqvist, Mikael S.; Skepö, Marie; Johansson, Eva

doi:10.1016/j.ijbiomac.2022.05.032

Cited by 11 publications

(10 citation statements)

References 96 publications

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“…To the best of our knowledge, there are no other works on gliadin peptides in solution at the atomistic level. Recent atomistic and coarse-grained Monte Carlo simulations of gliadins have been published, as well as bioinformatics and MD studies . These studies provide evidence that the regions of the protein that correspond to the peptides are disordered.…”

Section: Discussionmentioning

confidence: 99%

IDP Force Fields Applied to Model PPII-Rich 33-mer Gliadin Peptides

et al. 2023

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The 33-mer gliadin peptide and its deamidated metabolite, 33-mer DGP, are the immunodominant peptides responsible for the adaptive immune response in celiac disease (CD). CD is a complex autoimmune chronic disorder triggered by gluten ingestion that affects the small intestine and affects ∼1% of the global population. The 33-mers are polyproline II-rich (PPII) and intrinsically disordered peptides (IDPs), whose structures remain elusive. We sampled the conformational ensembles of both 33-mer peptides via molecular dynamics simulations employing two force fields (FFs) (Amber f f 03ws and Amber f f 99SB-disp) specifically validated for other IDPs. Our results show that both FFs allow the extensive exploration of the conformational landscape, which was not possible with the standard FF GROMOS53A6 reported before. Clustering analysis of the trajectories showed that the five largest clusters (78−88% of the total structures) present elongated, semielongated, and curved conformations in both FFs. Large average radius of gyration and solvent-exposed surfaces characterized these structures. While the structures sampled are similar, the Amber f f 99SB-disp trajectories explored folded conformations with a higher probability. In addition, PPII secondary structure was preserved throughout the trajectories (58−73%) together with a nonnegligible content of β structures (11−23%), in agreement with previous experimental results. This work represents the initial step in studying further the interaction of these peptides with other biologically relevant molecules, which could lead to finally disclose the molecular events that lead to CD.

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Section: Discussionmentioning

confidence: 99%

IDP Force Fields Applied to Model PPII-Rich 33-mer Gliadin Peptides

et al. 2023

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“…The mechanisms behind heat treatment-induced crosslinking are mainly related to the unwinding of secondary structures of the proteins and breaking of present crosslinks so that novel and additional crosslinks are able to form. 60 The temperature needed to have an impact on crosslinking reactions differs for various proteins, as do the ACS Omega ability of the proteins to crosslink. For the crambe proteins, secondary structure evaluations by FT-IR did not reveal any clear signs of increased crosslinking from moderate heat incubation at pH 10 before pressing.…”

Section: Modification Of Proteinmentioning

confidence: 99%

Green Chemistry to Modify Functional Properties of Crambe Protein Isolate-Based Thermally Formed Films

et al. 2023

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Proteins are promising precursors to be used in production of sustainable materials with properties resembling plastics, although protein modification or functionalization is often required to obtain suitable product characteristics. Here, effects of protein modification were evaluated by crosslinking behavior using high-performance liquid chromatography (HPLC), secondary structure using infrared spectroscopy (IR), liquid imbibition and uptake, and tensile properties of six crambe protein isolates modified in solution before thermal pressing. The results showed that a basic pH (10), especially when combined with the commonly used, although moderately toxic, crosslinking agent glutaraldehyde (GA), resulted in a decrease in crosslinking in unpressed samples, as compared to acidic pH (4) samples. After pressing, a more crosslinked protein matrix with an increase in βsheets was obtained in basic samples compared to acidic samples, mainly due to the formation of disulfide bonds, which led to an increase in tensile strength, and liquid uptake with less material resolved. A treatment of pH 10 + GA, combined either with a heat or citric acid treatment, did not increase crosslinking or improve the properties in pressed samples, as compared to pH 4 samples. Fenton treatment at pH 7.5 resulted in a similar amount of crosslinking as the pH 10 + GA treatment, although with a higher degree of peptide/irreversible bonds. The strong bond formation resulted in lack of opportunities to disintegrate the protein network by all extraction solutions tested (even for 6 M urea + 1% sodium dodecyl sulfate + 1% dithiothreitol). Thus, the highest crosslinking and best properties of the material produced from crambe protein isolates were obtained by pH 10 + GA and pH 7.5 + Fenton, where Fenton is a greener and more sustainable solution than GA. Therefore, chemical modification of crambe protein isolates is effecting both sustainability and crosslinking behavior, which might have an effect on product suitability.

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“…Like gluten, gliadin is only partially degraded by human digestive enzymes [ 17 , 18 ]. Gliadins form different protein aggregates under the physiologically relevant pH of 3.0 and 7.0, enabling the enzymes’ accessibility to other possible degradation positions [ 19 , 20 , 21 ]. Recently, it was demonstrated that the gliadin peptides obtained after pepsin proteolysis behave as an amyloid-like structure associated with inflammatory cytokine production and pro-apoptotic mRNA expression [ 22 ].…”

Section: Introductionmentioning

confidence: 99%

Celiac Disease and Possible Dietary Interventions: From Enzymes and Probiotics to Postbiotics and Viruses

Wagh

Lammers²,

Padul

et al. 2022

IJMS

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Celiac Disease (CeD) is a chronic small intestinal immune-mediated enteropathy caused by the ingestion of dietary gluten proteins in genetically susceptible individuals. CeD is one of the most common autoimmune diseases, affecting around 1.4% of the population globally. To date, the only acceptable treatment for CeD is strict, lifelong adherence to a gluten-free diet (GFD). However, in some cases, GFD does not alter gluten-induced symptoms. In addition, strict adherence to a GFD reduces patients’ quality of life and is often a socio-economic burden. This narrative review offers an interdisciplinary overview of CeD pathomechanism and the limitations of GFD, focusing on current research on possible dietary interventions. It concentrates on the recent research on the degradation of gluten through enzymes, the modulation of the microbiome, and the different types of “biotics” strategies, from probiotics to the less explored “viromebiotics” as possible beneficial complementary interventions for CeD management. The final aim is to set the context for future research that may consider the role of gluten proteins and the microbiome in nutritional and non-pharmacological interventions for CeD beyond the sole use of the GFD.

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Clustering and cross-linking of the wheat storage protein α-gliadin: A combined experimental and theoretical approach

Cited by 11 publications

References 96 publications

IDP Force Fields Applied to Model PPII-Rich 33-mer Gliadin Peptides

IDP Force Fields Applied to Model PPII-Rich 33-mer Gliadin Peptides

Green Chemistry to Modify Functional Properties of Crambe Protein Isolate-Based Thermally Formed Films

Celiac Disease and Possible Dietary Interventions: From Enzymes and Probiotics to Postbiotics and Viruses

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