Gliadin

The gluten proteins from wheat, barley and rye are responsible both for celiac disease (CD) and for non-celiac gluten sensitivity, two pathologies affecting up to 6-8% of the human population worldwide. The wheat α-gliadin proteins contain three major CD immunogenic peptides: the p31-43, which induces the innate immune response; the 33-mer, formed by six overlapping copies of three highly stimulatory epitopes; and an additional DQ2.5-glia-α3 epitope which partially overlaps with the 33-mer. NGS and Sanger sequencing of α-gliadin genes from diploid and polyploid wheat provided six types of α-gliadins (named 1 to 6) with strong differences in their frequencies in diploid and polyploid wheat, and in the presence and abundance of these CD immunogenic peptides. Immunogenic variants of the p31-43 peptide were found in most of the α-gliadins. Variants of the DQ2.5-glia-α3 epitope were associated with specific types of α-gliadins. Remarkably, only Type 1 α-gliadins contained 33-mer epitopes...

• Romer Labs’ AgraStrip® Gluten G12 is an immunochromatographic lateral flow assay for the
qualitative detection of gluten at thresholds of 5, 10 and 20 ppm in foods, rinse water and
environmental surfaces.
• G12 antibody targets a 33-mer peptide that is resistant to enzymatic digestion and heat
denaturation, as well as being the fragment of the gliadin protein to which Celiac Disease sufferers
react, making it a reliable analytical marker.
• G12 also cross-reacts with barley hordein, rye secalin and oat avenin.
• This study was conducted to validate the AgraStrip® Gluten G12 assay method under the guidance
of the AOAC Performance Tested MethodsSM program against AOAC OMA 2012.01 in rice flour,
bread, incurred bread, cookie, ice cream and chocolate matrices, and stainless steel environmental
surface.
• Matrix studies demonstrated that AgraStrip® Gluten G12 will detect spiked gluten and gliadin at
varying spike levels and assay thresholds in challenging matrices.
• The assay demonstrated no cross-reactivity or interference against 38 additional gluten-free
matrices, and proved its overall suitability as AOAC PTM-certified.

In this article it is proposed that celiac disease be viewed not as a rare “genetically-determined” disorder, but as an extreme example of our body communicating to us a once universal, species-specific affliction: severe intolerance to wheat. Celiac disease reflects back to us how profoundly our diet has diverged from what was, until only recently a grain free diet, and even more recently, a wheat free one. We are so profoundly distanced from that dramatic Neolithic transition in cultural time that “missing is any sense that anything is missing.” The body, on the other hand, cannot help but remember a time when cereal grains were alien to the diet, because in biological time it was only moments ago.

specificity of 99.3% (CI, 98.0% to 99.9%), and negative predictive value of 99.3% (CI, 98.0% to 99.9%). Testing positive for either HLA-DQ type maximized sensitivity (100% (CI, 79% to 100%)) and negative predictive value (100% (CI, 98.6% to 100%)), whereas testing negative for both minimized the negative likelihood ratio (0.00 (CI, 0.00 to 0.40)) and posttest probability (0% (CI, 0%

The effect of low levels of nitrogen, phosphorus and a combination of the two on the distribution of polymeric and monomeric proteins in two high quality spring bread wheat cultivars was investigated for two consecutive seasons. Size exclusion-high performance liquid chromatography (SE-HPLC) was used to determine the quantity and relationships of monomeric and polymeric proteins, and their relationship with flour protein content (FPC) and SDS sedimentation volume (SDSS). The low nitrogen and combined low nitrogen and low phosphorus treatments had a much larger effect on the protein fractions than the low phosphorus treatment alone. The SDS-soluble large monomeric protein fraction and the percentage SDS-insoluble monomeric proteins, were significantly increased under low nitrogen and a combination of low nitrogen and low phosphorus treatments. The percentage SDS-insoluble large and total polymeric proteins was significantly reduced under low nitrogen and a combination of low nitrogen and phosphorus treatments. The SDS-soluble and-insoluble small polymeric proteins were significantly increased under both low nitrogen and a combination of low nitrogen and low phosphorus treatments. The low nitrogen treatment consistently caused the lowest FPC and SDSS values. Under low nitrogen conditions, there was a significant positive correlation between the SDS-soluble gliadins and SDSS, and FPC.

There is an urgent clinical need for a better laboratory celiac disease diagnosis with both less false positive results and minimal underdetection. The aim of the present study was to evaluate the performance and diagnostic accuracy of different assays in an outpatient population setting for the diagnosis for celiac disease (CD) in order to design an optimal algorithm. We used 15 different ELISA assays to assess 47 blood samples of newly diagnosed children (positive biopsy results) and 52 samples from age- and sex-matched children with negative biopsy results for CD. Scoring criteria were established for grading the assays performance and characteristics. The combined gliadin and tTG assays exhibited the best sensitivity (100%). The addition of other assays to the CeliCheck neo-epitopes assay improved specificity so that the final algorithm had 100% sensitivity, 96.2% specificity, and 98.1% accuracy. The clinical demand for both maximal sensitivity and maximal specificity cannot be achieved with a single test. Using a combination of a sensitive assay together with specific assays improved celiac disease detection rates, with an acceptable number of false positive results. This model, however, needs to be confirmed prospectively in both children and adults.

To explore the natural history of antibodies against tissue transglutaminase (TGA), endomysium (EMA), reticulin (ARA), and gliadin (AGA-IgG and AGA-IgA) in children carrying HLA-conferred risk for celiac disease (CD) and observed frequently from birth. TGA was measured in serum samples obtained between years 2000 and 2003 from 1,320 children carrying genetic CD risk. If a sample was TGA positive, all five antibodies were analyzed in all banked and forthcoming samples from that child, and a duodenal biopsy was recommended. At the end of this observation, in August 2004, the age of the children was from 1 to 9.5 yr (mean 4.1 yr). Forty-nine children (3.7%) were TGA positive. In these children, AGA-IgG had emerged at the mean age (+/- SD, range) of 2.0 +/- 1.5, 0.5-6.6 yr, while TGA, EMA, and ARA all emerged concurrently somewhat later (TGA at 3.2 +/- 1.5, 1.0-7.0 yr, P < 0.001 when compared to AGA-IgG). Despite continuing gluten exposure, positive TGA, EMA, ARA, AGA-IgA, and AGA-Ig...

BACKGROUND: With the increasing demand for high-quality foodstuffs and concern for environmental sustainability,
late-season nitrogen (N) foliar fertilization of common wheat is now an important and widespread practice. This study
investigated the effects of late-season foliar versus soil N fertilization on yield and protein content of four varieties of durum
wheat, Aureo, Ariosto, Biensur and Liberdur, in a three-year field trial in northern Italy.
RESULTS: Variations in low-molecular-weight glutenins (LMW-GS), high-molecular-weight glutenins (HMW-GS) and gliadins
were assessed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). It was found that N applied to the
canopy did not improve protein rate compared with N application to the soil (general mean 138mg g−1), but moderately
increased productivity in the high-yielding varieties Liberdur and Biensur (three-year means 7.23 vs 7.13 and 7.53 vs 7.09 t
ha−1 respectively). Technological quality was mainly related to variety choice, Aureo and Ariosto having higher protein rates
and glutenin/gliadin ratios. Also found was a strong ‘variety × N application method’ interaction in the proportions of protein
subunits within each class, particularly LMW-GS and gliadins. A promising result was the higher N uptake efficiency, although
as apparent balance, combined with higher HMW/LMW-GS ratio in var. Biensur.
CONCLUSION: Late-season foliar N fertilization allows N fertilizer saving, potentially providing environmental benefits in the
rainy climate of the northern Mediterranean area, and also leads to variety-dependent up-regulation of essential LMW-GS and
gliadins. Variety choice is a key factor in obtaining high technological quality, although it is currently associated with modest
grain yield. This study provides evidence of high quality in the specific high-yielding variety Biensur, suggesting its potential as
amono-varietal semolina for pasta production.

Triticum turgidumsubsp.durumwas grown according to four farming systems: conventional (CONV), organic with cow manure (OMAN) or green manure (OLEG), and without inputs (NOINPUT). Some chemical and technological characteristics differed between CONVand organic flours. As shown by two-dimensional electrophoresis (2-DE) analysis, OMANand OLEGflours showed the highest number of gliadins, and OMANflour also had the highest number of high-molecular-mass glutenins. Type I sourdoughs were prepared at the laboratory level through a back-slopping procedure, and the bacterial ecology during sourdough preparation was described by 16S rRNA gene pyrosequencing. Before fermentation, the dough made with CONVflour showed the highest bacterial diversity. Flours were variously contaminated by genera belonging to theProteobacteria,Firmicutes, andActinobacteria. Mature sourdoughs were completely and stably dominated by lactic acid bacteria. The diversity ofFirmicuteswas the highest for mature sourdoughs...

Immunoglobulin A tissue transglutaminase is the single most efficient serological test for the diagnosis of celiac disease. It is well known that immunoglobulin A tissue transglutaminase levels correlate with the degree of intestinal damage, and that values can fluctuate in patients over time. Serological testing can be used to identify symptomatic individuals that need a confirmatory biopsy, to screen at-risk populations or to monitor diet compliance in patients previously diagnosed with celiac disease. Thus, interpretation of serological testing requires consideration of the full clinical scenario. Antigliadin tests are no longer recommended for the diagnosis of classical celiac disease. However, our understanding of the pathogenesis and spectrum of gluten sensitivity has improved, and gluten-sensitive irritable bowel syndrome patients are increasingly being recognized. Studies are needed to determine the clinical utility of antigliadin serology in the diagnosis of gluten sensitiv...

Romer Labs , Inc. developed an immunochromatographic lateral flow assay for the qualitative detection of gluten in raw ingredients, processed foods, finished food products, and environmental surfaces, using the G12 antibody developed by Belén Morón. The G12 antibody targets a 33-mer peptide which is resistant to enzymatic digestion and heat denatiuration, as well as being the fragment of the gliadin protein.to which celiac disease sufferers react, making it a reliable analytical marker. This study was performed to validate the AgraStrip® GlutenG12 assay method under the guidance of the AOAC Peiformance Tested MethodsSM (PTM) program against AOAC Official Method of AnalysisSM 2012.01 in rice flour, bread, cookie, ice cream, and chocolate matrixes spiked with either purified gliadin or wheat gluten standard at 0, 3, 8, 15, and 25 ppm concentrations and tested at the 5, 10, and 20 ppm assay thresholds, as well as on, environmental surfaces. Stability, robustness, variation, and lot con...

Immunogenic gluten proteins implicated in celiac disease (CD) largely resist degradation by human digestive enzymes. Here we pursued the isolation of gluten-degrading organisms from human feces, aiming at bacteria that would digest gluten under acidic conditions, as prevails in the stomach. Bacteria with gluten-degrading activities were isolated using selective gluten agar plates at pH 4.0 and 7.0. Proteins in concentrated bacterial cell sonicates were separated by diethylaminoethanol chromatography. Enzyme activity was monitored with chromogenic substrates and gliadin zymography. Elimination of major immunogenic gluten epitopes was studied with R5 and G12 enzyme-linked immunosorbent assays. Gliadin-degrading enzyme activities were observed for 43 fecal isolates, displaying activities in the ~150-200 and <50 kDa regions. The active strains were identified as Pseudomonas aeruginosa. Gliadin degradation in gel was observed from pH 2.0 to 7.0. Liquid chromatography-electrospray ioni...