Wheat Gliadin Research Articles

Effect of covalent conjugation with chlorogenic acid and luteolin on allergenicity and functional properties of wheat gliadin

In order to develop hypoallergenic wheat products, this study investigated the reduction in allergenicity and improvement in functional properties of wheat gliadin (Gli) through covalent conjugation with chlorogenic acid (CA) and luteolin (LU), as well as the mechanism of covalent conjugation. The upward shifted of the electrophoresis band and the decrease of retention time of chromatographic peak suggested the molecular weight of Gli became larger, and the covalent conjugation was confirmed. Gli was covalently conjugated with CA/LU via the free amino, thiol and tyrosine groups. The grafting rate results showed the degree of covalent interaction between Gli and CA was greater than that of Gli-LU. The structure of Gli was altered distinctly after covalently conjugated with CA/LU, transforming to a more ordered structure. Western blot and ELISA analysis indicated that Gli-CA/LU conjugates showed the lower IgG binding capacity. Further, the thermal stability, antioxidant activity and in vitro digestibility of conjugates were significantly improved (p < 0.05). This research provided theoretical basis and guidance for the production of hypoallergenic wheat products.

Molecular dynamics simulation of α‐gliadin in ethanol/aqueous organic solvents

SummaryGliadin is an important protein present in cereals. Owing to its solubility in alcohol, gliadin contributes significantly to the field of food industry. However, at present, it is challenging to study the structural characteristics of gliadin at the molecular level because the exact 3‐D structure cannot be obtained using experimental methods. In this study, an α‐gliadin model was constructed by combining homology modelling, ab initio modelling, and threading methods to study the structural properties of gliadin in ethanol aqueous solution. Our results indicated that glutamine is a key element of α‐gliadin. Also, α‐gliadin exhibited relatively low hydrophilicity and high lipid solubility. Molecular dynamics simulations suggested that there are hydrogen bonds and van der Waals forces existed between α‐gliadin and ethanol molecules. This study has explored the structure of wheat gliadin and its conformation in different ethanol solutions and provides a deeper understanding towards the deacetylation mechanism and potential applications of α‐gliadin in the food industry.

Antidiabetic bio-peptides of soft and hard wheat glutens

The effects of various purification techniques on kiwifruit enzyme characteristics (protease activity, kinetic parameters, and protein patterns) and production of wheat gluten bio-active peptides were investigated. The enzyme extract purified by ammonium sulfate precipitation method exhibited the highest protease activity (26), Km (0.04 ± 0.002 mM), Kcat/Km (40), and yield (96%). Using actinidin, the hard and soft wheat gluten subunit proteins produced antidiabetic inhibitory (α-glucosidase and α-amylase) peptides. The smallest Mw fraction of soft wheat gliadin peptide (<1 kDa) showed the highest inhibitory capacity against α-glucosidase (18.4 ± 0.7%) and α-amylase (53.3 ± 1.9%). The presence of high levels of amino acids with hydroxyl groups and proline in P3 sub-fraction had a critical role on α-glucosidase (47.2%) and α-amylase (71.2%) inhibitory activities. In conclusion, wheat gluten subunit peptides showed significant metabolic effects relevant to glucose and insulin control in vitro.

Formation of protein-anthocyanin complex induced by grape skin extracts interacting with wheat gliadins: Multi-spectroscopy and molecular docking analysis

In order to broaden the application of grape skin anthocyanin extract (GSAE) in flour products, the interaction of gliadin (Gli) and GSAE were investigated. Seven anthocyanin components from GSAE were identified by HPLC-MS2, which could form complexes with Gli having different binding rates based on UV, FTIR and HPLC analysis. The fluorescence quenching experiment showed that GSAE was capable of efficiently quenching the intrinsic fluorescence of Gli through hydrophobic interactions, and the binding parameters were near to one unit at the given temperatures. Additionally, GSAE binding changed the conformational properties of Gli, increasing α-helix and β-turn content, but decreasing β-sheet and irregular coil content. The molecular docking suggested that Gli possessed various binding sites bound with different anthocyanin monomers, mainly depending on hydrogen bonds and hydrophobic interactions. These findings further proved the formation of Gli-GSAE complex, indicating the potential of anthocyanins as natural colorant.

Dynamic high‐pressure microfluidization enhanced the emulsifying properties of wheat gliadin by rutin

Dynamic high-pressure microfluidization (DHPM) has attracted increasing interest in food macromolecule modification, which has been used in the preparation of nanoemulsions, gel-like soy protein emulsions, and nanocelluloses. This study explored the effects of DHPM under 0, 40, 80, 120, and 160 MPa with the addition of rutin on the physical, structural, rheological, and morphological characteristics of wheat gliadin. Infrared spectrum analysis showed that the DHPM treatment resulted in the structural changes of wheat gliadin and the primary interactions between wheat gliadin and rutin were hydrogen bond and hydrophobic effects. Here, 120 MPa DHPM treatment with the addition of rutin caused decreased particle sizes but increased zeta-potential and viscoelastic properties of wheat gliadin, with particle sizes at 245.20 nm and zeta-potential at 21.76 mV, respectively. The results showed that the combination of DHPM treatment at 120 MPa and rutin to wheat gliadin exhibited the morphology of nanospheres with a more compact structure, uniform particle distribution, and fine emulsifying properties. Practical applications The interaction between protein and polyphenol are able to preserve the stability of the functional compounds, allow targeted and controlled release, improve texture in the food industry. Improvement of functional characteristics of protein-polyphenol complexes with high emulsifying stability during food processing is crucial to use in the food industry. Therefore, the goal of this research is to use a soluble complex of gliadin-rutin for the development of its functional characteristics.

Microbial transglutaminase induced modification of wheat gliadin based nanoparticles and its impact on their air-water interfacial properties

There is a growing interest in plant protein based nanoparticles (NPs) such as wheat gliadin NPs (GNPs) for stabilizing foams in food systems. To increase the range of their applications, it is necessary to understand the role of different gliadin types and to tailor their behavior at air-water (A-W) interfaces. The latter is here done by modifying GNPs with microbial transglutaminase (TG). The most pronounced solubility loss of ω-gliadins (by 36.1%) after TG treatment at pH 4.5, measured by reversed phase high performance liquid chromatography (RP-HPLC), indicated that this protein type was more susceptible to TG action than α-gliadins and γ-gliadins, the solubility losses of which were 11.2 and 11.4% respectively. The lack of intramolecular disulfide bonds in ω-gliadins but not in the other gliadin types likely resulted in a greater accessibility of the lysine residues and thus more pronounced susceptibility of ω-gliadins to the enzyme. Interestingly, TG treatment of GNPs notably improved their foaming properties at pH 4.5 (and thus below the gliadin pI). The high surface dilatational modulus value of TG treated GNPs, when compared to control GNPs (53.9 and 32.7 mN/m, respectively), indicated formation of a strong viscoelastic A-W interfacial protein film, presumably due to the presence of TG catalyzed intermolecular isopeptide bonds. Fractionation of foams stabilized by (un-)treated GNPs and subsequent RP-HPLC analysis of the foam and liquid fractions showed that γ-gliadins were more important for A-W interface stability than ω-gliadins even if the latter were most affected by the TG treatment. Elimination of positively charged (at pH 4.5) lysine residues and conformational changes (both as a result of TG treatment) may have altered the ability of ω-gliadins to adsorb at the interface and to interact with other proteins thereat. Overall, TG treatment of GNPs resulted in formation of very strong protein films at the A-W interface stabilized by both covalent bonds and non-covalent interactions which in turn led to highly stable foams.

Transamidated wheat gliadin induces differential antigen recognition in the small intestine of HLA/DQ8 transgenic mice.

A lifelong gluten-free diet (GFD) is currently the only available therapy for coeliac disease (CD). However, GFD compliance is difficult and alternative strategies are envisaged in the near future. We previously found that wheat gliadin following transamidation by microbial transglutaminase (mTG) does not induce IFN-γ secretion by intestinal T cells from CD patients. Fully transamidated gliadin with lysine ethyl ester can be recovered in a soluble protein fraction (spf) generated by the enzymatic treatment of wheat flour. Herein, we analysed the performance of transamidation by mTG on a pilot-scale (1L) by evaluating the reaction kinetics and its biological effect on the intestinal immune response in HLA/DQ8 transgenic mice, a model of gluten sensitivity. At 1 h, all gliadin fractions showed a faster electrophoretic mobility by acid-polyacrylamide gel electrophoresis (A-PAGE) following transamidation in comparison with their native counterparts. In parallel, the yield of residual native gliadin dropped (30% at 180 min), confirming our previous findings on a lab scale. Mucosal sensitisation of mice with gliadin via the intranasal route induced a Th1 phenotype in mesenteric lymph nodes (MLNs). Importantly, IFN-γ secretion was significantly reduced when gliadin-specific MLN cells were challenged in vitro with spf (P < 0.001). Multiplex analysis revealed that the adaptive immune response evoked by spf involved a distinct cell population characterised by secretion of IL-2, IL-3 and IL-5. Notably, spf stimulated in vitro a reduced or null secretion of all of the examined pro-inflammatory markers mainly associated to innate immunity. In conclusion, our data revealed the ability of transamidated gliadin to modulate both innate and adaptive mechanisms involved in the inflammatory response induced by wheat gliadin in the small intestine of DQ8 mice.

Effect of additional water supply during grain filling on protein composition and epitope characteristics of winter oats

Pure oats in gluten-free diets (GFD) represent important nutritional benefits for people suffering from celiac disease (CD). However, oat cultivars do not contain the typical CD-related wheat gliadin analog polypeptides. Emerging evidence suggests that oat cultivars containing gluten-like epitopes in avenin sequences may pose potential health risks for celiac patients in rare cases, depending on the individual’s susceptibility. Consequently, it is necessary to screen oats in terms of protein and epitope composition, to be able to select safe varieties for gluten-free applications. The overall aim of our study is to investigate the variation of oat protein composition directly related to health-related and techno-functional properties and to examine how the protein compositional parameters change due to irrigation during the grain-filling period as compared to the natural rain-fed grown, in a large winter oat population of different geographic origin.Elements of an oat sample population representing 164 winter oat varieties from 8 countries and the protein composition of resulting samples have been characterized. Size distribution of the total protein extracts has been analyzed by SE-HPLC, while the 70% ethanol extracted proteins were analyzed by RP-HPLC. Protein extracts are separated into 3 main groups of fractions on the SE-HPLC column; polymeric, avenin, and non-avenin monomeric protein groups, representing 59.17–80.87%, 12.89–31.03%, and 3.40–9.41% of total protein content, respectively. The ratio of polymeric to monomeric proteins varied between 1.71 and 6.07. 91 RP-HPLC-separated peaks have been differentiated from the ethanol extractable proteins of the entire population.The various parameters identified a lot of variation, confirming the significance of genotypic variation. In addition, it was also established that the additional water supply during grain filling significantly affected the various quantitative parameters of protein content, but not its qualitative structure. This environmental effect, however, was strongly genotype-dependent. Winter oat genotypes with low levels of epitope content were identified and it was proven that these characteristics were independent of the environmental factor of water availability. These genotypes are appropriate for initiating a specific breeding program to yield oat cultivars suitable for CD patients.

Characterization of gliadin, secalin and hordein fractions using analytical techniques

Prolamins, alcohol soluble storage proteins of the Triticeae tribe of Gramineae family, are known as gliadin, secalin and hordein in wheat, rye and barley respectively. Prolamins were extracted from fifteen cultivars using DuPont protocol to study their physiochemical, morphological and structural characteristics. SDS-PAGE of prolamins showed well resolved low molecular weight proteins with significant amount of albumin and globulin as cross-contaminant. The β-sheet (32.72–37.41%) and β-turn (30.36–37.91%) were found higher in gliadins, while α-helix (20.32–28.95%) and random coil (9.05–10.28%) in hordeins. The high colloidal stability as depicted by zeta-potential was observed in gliadins (23.5–27.0 mV) followed secalins (11.2–16.6 mV) and hordeins (4.1–7.8 mV). Surface morphology by SEM illustrated the globular particle arrangement in gliadins, sheet like arrangement in secalins and stacked flaky particle arrangement in hordeins fraction. TEM studies showed that secalin and hordein fractions were globular in shape while gliadins in addition to globular structure also possessed rod-shaped particle arrangement. XRD pattern of prolamin fractions showed the ordered crystalline domain at 2θ values of 44.1°, 37.8° and 10.4°. The extracted prolamins fractions showed amorphous as well as crystalline structures as revealed by XRD and TEM analysis. Space saving hexagonal molecular symmetry was also observed in TEM molecular arrangement of prolamins which has profound application in development of plant-based polymers and fibres.

Optimization of large-scale purification of omega gliadins and other wheat gliadins

Among wheat storage proteins, omega-gliadins display a singular amino acid sequence only composed by repetitive sequences. They have been described as a major wheat allergen and also contain T-cell epitopes implicated in coeliac disease. To study the structural and biophysical properties of omega-gliadins and other gliadins (e.g., gluten network formation, allergic response), highly purified and concentrated fractions are needed. In the present work, we used chromatography media screening to improve their fractionation. A S Ceramic Hyper D (Pall) resin was selected for its ability to concentrate omega-gliadins in the first elution peaks. Gamma- and beta-gliadins were then separated by hydrophobic interaction chromatography and eluted with an ethanol gradient. Alpha-gliadins were purified by gel filtration. Each fraction was characterized by electrophoresis and reverse phase HPLC. The developed preparative protocol enabled the purification of several grams of highly purified gliadins to the detriment of the yield.

Influence of the Physico-Chemical Properties of Model Compounds on the Mean Sizes and Retention Rate of Gliadin Nanoparticles

Vegetal proteins have emerged as appealing starting materials for the development of various drug delivery systems, and their use for obtaining polymeric nanoparticles has been profitably exploited in multidisciplinary fields. Wheat gliadin, the water-insoluble storage protein of gluten, is characterized by a great amount of hydrophobic amino acid residues and notable mucoadhesive features. This biopolymer can be easily manipulated to form colloidal carriers, films and fibers by means of bio-acceptable solvents and easy preparation procedures. In this investigation, four model compounds characterized by different octanol/water partition coefficient (logP) values were encapsulated in gliadin nanoparticles, with the aim of investigating the influence of their physico-chemical properties on the cargo features and technological characteristics of the protein nanocarriers. The results demonstrate that the chemical structure, solubility and molecular weight of the compounds used are able to dramatically modulate the mean sizes and the entrapment efficiency of gliadin nanoparticles. This demonstrates the importance of a preformulation investigation when a molecule needs to be encapsulated in this type of polymeric carrier.

Influence of konjac glucomannan on thermal and microscopic properties of frozen wheat gluten, glutenin and gliadin

The effects of different konjac glucomannan (KGM) concentrations (0.5%, 1.5%, 2.5%, 3.5%, 4.5%, w/w) on the thermal and microscopic properties of the frozen wheat gluten, glutenin and gliadin were investigated in this study. KGM exerted a positive effect on the denaturation temperature and denaturation enthalpy of frozen gluten and gliadin, while KGM decreased those of frozen glutenin. Such effects induced by KGM were resulted from the interaction between KGM and frozen wheat gluten, glutenin and gliadin. The underlying mechanism was discussed from the perspective of protein structure. Specifically, the addition of KGM increased the α-helix structure of frozen gluten and gliadin, while decreased the α-helix of frozen glutenin. Furthermore, β-turn of frozen gluten and gliadin presented a decreasing trend with increasing amount of KGM. Scanning electron microscopy confirmed that there was stronger interaction between wheat protein and KGM. These results provide fundamental knowledge for better application of KGM in frozen protein-based foods.

Investigation of Protein and Epitope Characteristics of Oats and Its Implications for Celiac Disease.

The use of pure oats (oats cultivated with special care to avoid gluten contamination from wheat, rye, and barley) in the gluten-free diet (GFD) represents important nutritional benefits for the celiac consumer. However, emerging evidence suggests that some oat cultivars may contain wheat gliadin analog polypeptides. Consequently, it is necessary to screen oats in terms of protein and epitope composition to be able to select safe varieties for gluten-free applications. The overall aim of our study is to investigate the variability of oat protein composition directly related to health-related and techno-functional properties. Elements of an oat sample population representing 162 cultivated varieties from 20 countries and the protein composition of resulting samples have been characterized. Size distribution of the total protein extracts has been analyzed by size exclusion-high performance liquid chromatography (SE-HPLC) while the 70% ethanol-extracted proteins were analyzed by RP-HPLC. Protein extracts separated into three main groups of fractions on the SE-HPLC column: polymeric proteins, avenins (both containing three subgroups based on their size), and soluble proteins, representing respectively 68.79–86.60, 8.86–27.72, and 2.89–11.85% of the total protein content. The ratio of polymeric to monomeric proteins varied between 1.37 and 3.73. Seventy-six reversed phase-HPLC-separated peaks have been differentiated from the ethanol extractable proteins of the entire population. Their distribution among the cultivars varied significantly, 6–23 peaks per cultivar. The number of appearances of peaks also showed large variation: one peak has been found in 107 samples, while 15 peaks have been identified, which appeared in less than five cultivars. An estimation method for ranking the avenin-epitope content of the samples has been developed by using MS spectrometric data of collected RP-HPLC peaks and bioinformatics methods. Using ELISA methodology with the R5 antibody, a high number of the investigated samples were found to be contaminated with wheat, barley, or rye.

FT-Raman Spectroscopy as a Tool to Study the Secondary Structures of Wheat Gliadin Proteins.

Raman spectroscopy is a useful method in biological, biomedical, food, and agricultural studies, allowing the simultaneous examination of various chemical compounds and evaluation of molecular changes occurring in tested objects. The purpose of our research was to explain how the elimination of ω-fractions from the wheat gliadin complex influences the secondary structures of the remaining αβγ-gliadins. To this aim, we analyzed the endosperm of wheat kernels as well as gliadin proteins extracted from two winter wheat genotypes: wasko.gl+ (control genotype containing the full set of gliadins) and wasko.gl− (modified genotype lacking all ω-gliadins). Based on the decomposition of the amide I band, we observed a moderate increase in β-forms (sheets and turns) at the expense of α-helical and random coil structures for gliadins isolated from the flour of the wasko.gl− line. Since ω-gliadins contain no cysteine residues, they do not participate in the formation of the disulfide bridges that stabilize the protein structure. However, they can interact with other proteins via weak, low-energetic hydrogen bonds. We conclude that the elimination of ω-fractions from the gliadin complex causes minor modifications in secondary structures of the remaining gliadin proteins. In our opinion, these small, structural changes of proteins may lead to alterations in gliadin allergenicity.

Pro-Pre and Postbiotic in Celiac Disease

Celiac Disease (CD) is an autoimmune disease characterized by inflammation of the intestinal mucosa due to an immune response to wheat gliadins. It presents in subjects with genetic susceptibility (HLA-DQ2/DQ8 positivity and non-HLA genes) and under the influence of environmental triggers, such as viral infections and intestinal microbiota dysbiosis. The only treatment currently available in CD is a gluten-free diet for life. Despite this, the intestinal dysbiosis that is recorded in celiac subjects persists, even with adherence to dietary therapy. In this review, we have analyzed the literature over the past several decades, which have focused on the use of pro-, pre- and post-biotics in vitro and in vivo in CD. The study of probiotics and their products in CD could be interesting for observing their various effects on several different pathways, including anti-inflammatory properties.

Description of a clinical case of combination of celiac disease and ichthyosis in a girl

Abstract Introduction. Celiac disease, or gluten-sensitive enteropathy, can be defined as a persistent intolerance of wheat gliadins and other cereal prolamines in the small intestinal mucosa of genetically susceptible individuals. The clinical picture of the disease can often be misleading because it varies greatly from patient to patient, resulting in delayed diagnosis.To analyze the clinical case of a child with celiac disease and acquired ichthyosis.Results.The disease, until a final diagnosis was established, had a severe course due to gastrointestinal and dermatological disorders. From the age of 1.5 years, the child had frequent diarrhea, bloating, which is why she was repeatedly hospitalized in the hospital at the place of residence. However, there was no effect from the ongoing therapeutic measures, and other symptoms such as vomiting, peripheral edema, deficiency of height and weight, and severe peeling of the skin joined in. The diagnosis was finally confirmed at the age of 2.5 years after the test for antibodies to tissue transglutaminase IgA (fifty-fold excess relative to the norm). A genetic study revealed alleles of genes responsible for predisposition to celiac disease. The results of a biopsy of the mucous membrane of the duodenum had signs of atrophy, lymphoid infiltration, corresponding to a lesion of the small intestine according to the classification Marsh III. Microscopic examination of the skin – hyperkeratosis with a decrease in the granular layer. On the basis of the obtained data, the diagnosis was made: Celiac disease, active phase, severe course, complicated by proteinenergy insufficiency severe degree, exudative enteropathy syndrome, 2 degree anemia, concomitant diagnosis: acquired ichthyosis. The girl was prescribed a gluten-free diet, and symptomatic drug therapy was carried out. In dynamics, the condition has improved. After 6 months, at the second visit, gastrointestinal and skin symptoms were absent, physical development was age-appropriate.Conclusions.The classic form of celiac disease usually manifests itself with several major symptoms, such as diarrhea, abdominal pain, weight loss, and nutritional deficiencies. In this article we wanted to talk about a rare combination of celiac disease with ichthyosis, therefore, practitioners should be wary of a combination of skin and gastrointestinal symptoms.

Impact and mechanism of sulphur-deficiency on modern wheat farming nitrogen-related sustainability and gliadin content

Two challenges that the global wheat industry is facing are a lowering nitrogen-use efficiency (NUE) and an increase in the reporting of wheat-protein related health issues. Sulphur deficiencies in soil has also been reported as a global issue. The current study used large-scale field and glasshouse experiments to investigate the sulphur fertilization impacts on sulphur deficient soil. Here we show that sulphur addition increased NUE by more than 20% through regulating glutamine synthetase. Alleviating the soil sulphur deficiency highly significantly reduced the amount of gliadin proteins indicating that soil sulphur levels may be related to the biosynthesis of proteins involved in wheat-induced human pathologies. The sulphur-dependent wheat gluten biosynthesis network was studied using transcriptome analysis and amino acid metabolomic pathway studies. The study concluded that sulphur deficiency in modern farming systems is not only having a profound negative impact on productivity but is also impacting on population health.

A biomimetic “intestinal microvillus” cell sensor based on 3D bioprinting for the detection of wheat allergen gliadin

A biomimetic “intestinal microvillus” electrochemical cell sensor based on three-dimensional (3D) bioprinting was developed, which can specifically and accurately detect wheat gliadin. Self-assembled flower-like copper oxide nanoparticles (FCONp) and hydrazide-functionalized multiwalled carbon nanotubes (MWCNT-CDH) were innovatively synthesized to improve the sensor performance. A conductive biocomposite hydrogel (bioink) was prepared by mixing FCONp and MWCNT-CDH based on GelMA gel. The cluster-shaped microvillus structure of small intestine was accurately printed on the screen printing electrode with the prepared bioink using stereolithography 3D-bioprinting technology, and then the Rat Basophilic Leukemia cells were immobilized on the gel skeleton. Next, the developed cell sensor was used to effectively detect wheat allergen gliadin. The experimental results show that the bioprinted cell sensor sensitively detects wheat gliadin when the optimized cell numbers and immobilized time are 1 × 106 cells/mL and 10 min, respectively. The linear detection range is 0.1–0.8 ng/mL, and the detection limit is 0.036 ng/mL. The electrochemical cell sensor based on 3D printing technology has excellent stability and reproducibility. Thus, a simple and novel electrochemical detection approach for food allergens was established in this study with potential application in food safety detection and evaluation.

Properties and Applications of Nanoparticles from Plant Proteins.

Nanoparticles from plant proteins are preferred over carbohydrates and synthetic polymeric-based materials for food, medical and other applications. In addition to their large availability and relatively low cost, plant proteins offer higher possibilities for surface modifications and functionalizing various biomolecules for specific applications. Plant proteins also avoid the immunogenic responses associated with the use of animal proteins. However, the sources of plant proteins are very diverse, and proteins from each source have distinct structures, properties and processing requirements. While proteins from corn (zein) and wheat (gliadin) are soluble in aqueous ethanol, most other plant proteins are insoluble in aqueous conditions. Apart from zein and gliadin nanoparticles (which are relatively easy to prepare), soy proteins, wheat glutenin and proteins from several legumes have been made into nanoparticles. The extraction of soluble proteins, hydrolyzing with alkali and acids, conjugation with other biopolymers, and newer techniques such as microfluidization and electrospraying have been adopted to develop plant protein nanoparticles. Solid, hollow, and core-shell nanoparticles with varying sizes and physical and chemical properties have been developed. Most plant protein nanoparticles have been used as carriers for drugs and as biomolecules for controlled release applications and for stabilizing food emulsions. This review provides an overview of the approaches used to prepare nanoparticles from plant proteins, and their properties and potential applications. The review’s specific focus is on the preparation methods and applications, rather than the properties of the proteins, which have been reported in detail in other publications.

Gliadin-mediated green preparation of hybrid zinc oxide nanospheres with antibacterial activity and low toxicity

The development of inorganic antibacterial agents that impart antibacterial properties to biomaterials has attracted wide attention. The paper introduced a kind of hybrid nanosphere antibacterial agent composed of wheat gliadin (WG) and zinc oxide (ZnO), with antibacterial efficacy and low toxicity. The ZnO/WG hybrid nanospheres were environment-friendly integrated by molecular self-assembly co-precipitating and freeze-drying transformation, and were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), atomic absorption spectroscopy (AAS), specific surface and pore size analysis, bacteriostasis test, reactive oxygen species (ROS) determination and safety evaluation. It was found that the prepared hybrid nanospheres were composed of two components, WG and ZnO, with a diameter scope of 100–200 nm; the content of ZnO in the hybrid nanospheres can reach 46.9–70.2% (w/w); the bacteriostasis tests proved that the prepared ZnO/WG nanospheres generating ROS, have a significant inhibitory effect on E. coli and S. aureus; furthermore, the ZnO/WG nanospheres are relatively safe and highly biocompatible in cells and mice. Therefore, the prepared novel ZnO/WG hybrid nanospheres were supposed to apply in the preparation of anti-infective wound dressings, tissue engineering skin scaffold materials, food, and cosmetics preservatives, and so on.