Immunoanalytic investigation of grain proteins antigenic for celiac disease patients in an einkorn collection

Our study focuses on the complex characterization of a wild and cultivated einkorn collection of the Cereal Gene Bank of Agriculture Research Institute in Hungary, using proteomics, immune analytics and bioinformatics analyses. In a serological ELISA pre-screen of 208 different Triticum monococcum L. ssp. monococcum and Triticum monococcum L. ssp. aegilopoides genotypes with celiac disease samples high diversity was observed in the immune response. Based on the immune analytic results, four genotypes with significantly reduced immune reactivity were selected for detailed proteomics characterization. Our results confirm the benefits of high-throughput/large-scale pre-screening and the use of a complex examination platform to get relevant information about the genetic diversity of celiac disease-relevant proteins in the analyzed einkorn genotypes. These genotypes cannot be incorporated into the daily diet of celiac patients; however, they may represent candidates – especially in combination with enzymatic treatments - to improve the lifestyle of individuals suffering from other clinical conditions like non-celiac wheat sensitivity

Ionic mechanisms limiting cardiac repolarization-reserve in humans compared to dogs.

The species-specific determinants of repolarization are poorly understood. This study compared the contribution of various currents to cardiac repolarization in canine and human ventricle. Conventional microelectrode, whole-cell patch-clamp, molecular biological and mathematical modelling techniques were used. Selective IKr block (50–100 nmol l−1 dofetilide) lengthened AP duration at 90% of repolarization (APD90) >3-fold more in human than dog, suggesting smaller repolarization reserve in humans. Selective IK1 block (10 μmol l−1 BaCl2) and IKs block (1 μmol l−1 HMR-1556) increased APD90 more in canine than human right ventricular papillary muscle. Ion current measurements in isolated cardiomyocytes showed that IK1 and IKs densities were 3- and 4.5-fold larger in dogs than humans, respectively. IKr density and kinetics were similar in human versus dog. ICa and Ito were respectively ∼30% larger and ∼29% smaller in human, and Na+–Ca2+ exchange current was comparable. Cardiac mRNA levels for the main IK1 ion channel subunit Kir2.1 and the IKs accessory subunit minK were significantly lower, but mRNA expression of ERG and KvLQT1 (IKr and IKsα-subunits) were not significantly different, in human versus dog. Immunostaining suggested lower Kir2.1 and minK, and higher KvLQT1 protein expression in human versus canine cardiomyocytes. IK1 and IKs inhibition increased the APD-prolonging effect of IKr block more in dog (by 56% and 49%, respectively) than human (34 and 16%), indicating that both currents contribute to increased repolarization reserve in the dog. A mathematical model incorporating observed human–canine ion current differences confirmed the role of IK1 and IKs in repolarization reserve differences. Thus, humans show greater repolarization-delaying effects of IKr block than dogs, because of lower repolarization reserve contributions from IK1 and IKs, emphasizing species-specific determinants of repolarization and the limitations of animal models for human disease

Mutáció kialakítása a Schizosaccharomyces pombe egyik transzkripciós regulátor génjében

A génexpresszió a gének kifejeződése, a genetikai információ megnyilvánulásának folyamata. Egyik legfontosabb eleme a transzkripció és annak szabályozása. A tanszkripciós szabályozás egyik központi eleme a Mediátor komplex. A Med31 a Mediátor komplex sok élőlényben konzerválódott azon komponense, amely részt vesz a több száz RNS polimeráz II szabályozta transzkripcióban. A kísérleteinkben a Schizosaccharomyces pombe hasadó élesztő med31-es génjét vizsgáltuk. Célunk az volt, hogy jobban megismerjük a gént, megtudjuk, hogy bizonyos génszakaszoknak van-e fontos szerepe a működésben. Ezért csonkolt mutánsokat hoztunk létre, és vizsgáltunk.BSc/BABiológiag

The Effect of Abiotic Stresses on the Protein Composition of Four Hungarian Wheat Varieties

Global climate change in recent years has resulted in extreme heat and drought events that significantly influence crop production and endanger food security. Such abiotic stress during the growing season has a negative effect on yield as well as on the functional properties of wheat grain protein content and composition. This reduces the value of grain, as these factors significantly reduce end-use quality. In this study, four Hungarian bread wheat cultivars (Triticum aestivum ssp. aestivum) with different drought and heat tolerance were examined. Changes in the size- and hydrophobicity-based distribution of the total proteins of the samples have been monitored by SE- and RP-HPLC, respectively, together with parallel investigations of changes in the amounts of the R5 and G12 antibodies related to celiac disease immunoreactive peptides. Significant difference in yield, protein content and composition have been observed in each cultivar, altering the amounts of CD-related gliadin, as well as the protein parameters directly related to techno-functional properties (Glu/Gli ratio, UPP%). The extent of changes largely depended on the timing of the abiotic stress. The severity of the negative effect depended on the growth stage in which abiotic stress occurred

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

The newly synthesized plant growth regulator S-methylmethionine salicylate may provide protection against high salinity in wheat

High salinity is one of the major environmental factors limiting the productivity of crop species worldwide. Improving the stress tolerance of cultivated plants and thus increasing crop yields in an environmentally friendly way is a crucial task in agriculture. In the present work the ability of a new derivative, S-methylmethionine-salicylate (MMS), to improve the salt tolerance of wheat plants was tested parallel with its related compounds salicylic acid and S-methylmethionine. The results show that while these compounds are harmful at relatively high concentration (0.5 mM), they may provide protection against high salinity at lower (0.1 mM) concentration. This was confirmed by gas exchange, chlorophyll content and chlorophyll-a fluorescence induction measurements. While osmotic adjustment probably plays a critical role in the improved salt tolerance, neither Na or K transport from the roots to the shoots nor proline synthesis are the main factors in the tolerance induced by the compounds tested. MMS, S-methylmethionine and Na-salicylate had different effects on flavonol biosynthesis. It was also shown that salt treatment had a substantial influence on the SA metabolism in wheat roots and leaves. Present results suggest that the investigated compounds can be used to improve salt tolerance in plants