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PubMed2000

Structural and immunochemical homologies between foxtail millet glutelin 60 kDa and starch granule-bound starch synthase proteins from rice, barley, corn and wheat grains.

Foxtail millet glutelin 60 kDa (MG60) was purified by preparative SDS-PAGE, and the N-terminal amino acid sequence was determined within 20 residues. The result demonstrated that the primary structure at N-terminal of MG60 was almost identical to those of the granule-bound starch synthase (GBSS) proteins from rice, barley, corn, wheat and potato. The existence of common epitopes among MG60 and GBSS proteins from these starch-storing cereals were corroborated by immunoblot analysis using antisera raised against MG60. These facts strongly suggest a close relationship between MG60-like glutelins and GBSS proteins.

Amino Acid Sequence↗
PubMed1977

Lectin purification on affinity columns containing reductively aminated disaccharides.

A method is described for isolating lectins in pure form and quantitative yield in a single step by affinity chromatography on aminoethyl polyacrylamide gels containing reductively aminated disaccharide residues. The affinity columns were prepared in two steps: (a) direct reductive amination of the disaccharide and aminoethyl gel with sodium cyanoborohydride in aqueous solution at pH 9; (b) N-acetylation of excess amino groups. Affinity columns prepared by reductive amination of lactose, melibiose, maltose, and di-N-acetylchitobiose were used to purify the following lectins: lactose, peanut, castor bean; melibiose, Bandeiraea simplicifolia; maltose, jack bean, common lentil; di-N-acetylchitobiose, wheat germ. These columns are extremely stable, have good flow rates, and high binding capacities.

Chromatography, Affinity↗
PubMedDate not supplied

[Determination of the tryptase level as diagnostic marker in food allergy in children].

BACKGROUND: during food provocation the mast cell degranulates causing the elevation of serum tryptase. AIM OF STUDY: the aim of our work was to estimate if tryptase level is the efficient diagnostic marker in case of IgE dependent food allergy in children. MATERIAL AND METHODS: the studied group (group I) consisted of 100 children (age 3-5 yrs) with IgE dependent food allergy confirmed by positive case history and allergy tests. The children presented an allergic reaction to one of the 3 most common food allergens - milk, egg and wheat flour proteins. Control group (group II) consisted of 31 healthy children. The open food provocation was performed only in the group I. Tryptase level was estimated before and 120 minutes after the food provocation. The FluoroEnzymeImmunoAssay method (FEIA) was used to assess the tryptase levels. RESULTS: baseline level of the tryptase in group I was significantly higher in comparison with group II. There was no significant difference between baseline level of the tryptase and level after the provocation. The decrease of the level of the tryptase after challenge was observed in 54% patients in group I. The increase of the tryptase level after the provocation was observed in 45% patients and in 1% patients the level of the tryptase was unchanged. CONCLUSIONS: 1. tryptase levels are not an effective marker in diagnostic of IgE dependent food allergy in children with allergic reaction to one or more food allergens, 2. patients with IgE dependent food allergy may have elevated level of tryptase with no clinical manifestation.

Allergens↗
PubMed1990

Glycoprotein storage in Gaucher disease: lectin histochemistry and biochemical studies.

Lectin histochemical studies were performed on formalin-fixed, frozen, and paraffin-embedded tissue sections from 19 patients with glucosylceramide lipidosis (i.e., Gaucher disease). Eleven different lectins were used to identify the specific carbohydrate residues in the undegraded stored compounds in the cytoplasm of Gaucher cells. In all cases studied, Gaucher cells stained with Concanavalia ensiformis agglutinin, Datura stramonium agglutinin, Lens culinaris, Ricinus communis agglutinin-I, and wheat germ agglutinin. These results demonstrated common carbohydrate residues in the undegraded material stored within Gaucher cells and indicated the presence of fucosylated N-linked complex oligosaccharides, and glycans containing N-acetyllactosamine repeating sequences, as well as nonreducing terminal beta-galactosyl and sialyl residues. In order to confirm these findings using biochemical methods, livers and spleens from Gaucher patients and controls, and from a patient with Niemann-Pick disease type C (included for comparison) were digested with Pronase and the resulting glycopeptides separated by gel filtration into fractions with high and low molecular weight. In the high-molecular-weight fractions from livers of Gaucher patients, the levels of sugars corresponding to N-linked glycans, as measured by gas-liquid chromatography, were elevated over those in controls. In the high-molecular-weight fractions from spleens, the levels of the same sugars were elevated in both Gaucher and Niemann-Pick type C patients. Digestion of the glycopeptides with endo-beta-galactosidase, which specifically cleaves polylactosaminoglycans, showed the presence of material containing N-acetyllactosamine repeating units in Gaucher liver glycopeptide fractions, but not in control and Niemann-Pick type C derived glycopeptide fractions. Our histochemical and biochemical studies demonstrated that in addition to glucosylceramide, affected tissues of patients with Gaucher disease accumulate glycoproteins. This accumulation could not have been predicted on the basis of the primary enzymatic defect.

Carbohydrates↗
PubMed1989

Active opioid binding protein from rat brain--a glycoprotein containing alpha-methyl-D-mannoside residues.

Active opioid binding protein was partially purified from rat brain by Vicia bungei Ohwi lectin (VBL). Mannose also existed in opioid receptors since the binding between opioid binding protein and VBL is specific, via alpha-methyl-D-mannoside (MeMan) residues. Since the active opioid binding protein purified by VBL chromatography was enriched about 200-folds. VBL can be used as effective purification tool which is much better than wheat germ agglutinin (WGA), a lectin commonly used in purifying opioid receptor.

Animals↗
PubMed1989

Examining protein translocation in cell-free systems and microinjected Xenopus oocytes.

A variety of assays have been developed which permit rapid and unambiguous determination of the membrane topology adopted by newly synthesized proteins. Cell-free systems and microinjected Xenopus oocytes are two of the most attractive approaches for characterizing the elements in both the nascent polypeptide and the membrane which together determine the final orientation of the protein in the membrane. Careful analysis of the mechanism of protein translocation using these methods has revealed a number of unusual topologies. The applications of a number of different assays for endoplasmic reticulum membrane translocation are described for the most commonly used cell-free systems (wheat germ and reticulocyte lysate), as well as for microinjected Xenopus oocytes.

Animals↗
PubMedDate not supplied

[Food allergy: recent findings].

Food allergy induces in infancy and childhood a large variety of symptoms which may be trivial in many children, chronic and severe in others and even fatal in rare cases. According to double-blind placebo controlled oral food challenges, cow's milk, egg, wheat and fish are the most common offending foods. Elimination of the offending food(s) is imperative for the management of children with food allergy. An appropriate formula without cow's milk proteins and allergenic epitopes should be given to infants with cow's milk allergy. Breast feeding and selected weaning after the sixth month of life are recommended for the prevention of food allergy in atopic prone babies.

Child↗
PubMed1998

Identification of zinc phosphide in a falsely labeled rodenticide bait.

"Kela" is a commercial rodenticide bait commonly used in Israel, made of wheat grains, which, according to its label, contains chlorophacinone. This product was involved in the death case of a man in which the victim's female companion was accused of assisting in this suicide and was subsequently convicted. Analysis of the wheat grains revealed zinc phosphide, whose use is restricted to authorized exterminators only, instead of chlorophacinone. Zinc phosphide was identified using microscopic examination, scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX) and X-ray powder diffraction (XRD).

Aged↗
PubMed1998

Interpreting skin prick tests in the evaluation of food allergy in children.

BACKGROUND: Skin prick tests (SPTs) are utilized routinely in the evaluation of food allergy and several authors have discussed their utility. Efforts to standardize SPT reagents and procedures have been made, but the accuracies of different recording techniques have not been clearly defined. The aim of this study was to compare different SPT recording methods with the outcome of oral food challenge and determine whether they offer any advantage over the criteria proposed by Bock and May (1). PATIENTS AND METHODS: Children suspected of IgE-mediated symptoms to any of five common food allergens (egg, milk, peanut, soy and wheat) were skin tested by the prick technique utilizing commercial extracts. The wheal reactions were recorded by two different methods: first by measuring the largest diameter of the wheal and the diameter orthogonal to it (mean wheal diameter), and second by recording the surface area of the wheal with a hand-held scanner. Wheal sizes above the 95% confidence interval of tolerant individuals were considered positive. The results of double-blind, placebo-controlled food challenges were considered the "gold standard" for diagnosis. Cut-off values were compared for positive responses in our study population (mean diameter/surface area of wheal): 4 mm/16 mm2 for egg, 5 mm/29 mm2 for milk, 6 mm/40 mm2 for peanut, 3 mm/9 mm2 for soy, and 3 mm/7 mm2 for wheat. RESULTS: Significant differences in wheal sizes were seen between individuals who were allergic or tolerant to egg (P < 0.001), milk (P < 0.001), wheat (P < 0.005), and peanut (P < 0.05). Reactivity to soy could not be predicted based on SPT results (P = n.s.). The sensitivities and the specificities of the two recording methods were similar. The predictive values were not significantly different from that of the commonly utilized method of grading SPTs (i.e. positive = mean diameter 3 mm or greater than the negative control). CONCLUSIONS: Skin prick tests are a useful procedure for evaluating clinical reactivity to egg, milk, peanut and wheat, but not to soy. While the size of the SPT wheals may be interpreted utilizing mean diameter or surface area cut-offs, the predictive values of these measurement methods were no better than the commonly utilized grading method where a positive skin test was recorded as a mean wheal diameter 3 mm greater than the negative control.

Allergens↗
PubMedDate not supplied

Reduced biodegradation of benzonitrile in soil containing wheat-residue-derived ash.

Burning of crop residues is a common agricultural practice that incorporates the resulting particulate matter (ash) of high adsorptivity into soils. To investigate the effect of ash on the biodegradation of pesticides in soils, we measured the sorption, desorption, and biodegradation of benzonitrile in a silt loam in the presence and absence of an ash resulting from burning of wheat (Triticum aestivum L.) residue. Biodegradation experiments were conducted by inoculating sorbent slurries with a pure culture of benzonitrile-degrading bacteria (Nocardia sp.). Both liquid- and sorbed-phase benzonitrile concentrations were quantified over time. The ash was approximately 2000 times more effective per unit mass than the soil in sorbing benzonitrile. Amendment of the soil with 1% ash (by weight) resulted in a 10-fold increase in sorption. Sorption of benzonitrile by the ash significantly decreased the solution-phase concentration in the slurries of ash and ash-amended soil. Desorption of benzonitrile from the ash required approximately 60 min to complete, whereas approximately 20 min were required for desorption from the soil. Benzonitrile in the extracts of various sorbents and soil slurry was completely degraded within 500 min. However, the degradation was substantially reduced in the presence of the ash. At 2000 min, only 20% of benzonitrile in ash slurry and only 44% in ash-amended soil slurry were degraded. An acclimation period of approximately 100 min was observed in extracts and slurries containing the ash. Substantial reduction in the biodegradation of benzonitrile in the presence of wheat ash was apparently due to sorption of benzonitrile by the ash, slow desorption from the ash, and the increased acclimation period. Our results suggest that the presence of crop-residue-derived ash may increase the persistence of pesticides in agricultural soils.

Adsorption↗
PubMed1996

Wheat retrotransposon families identified by reverse transcriptase domain analysis.

Variations in the reverse transcriptase domain were analyzed to clarify the family structure of retrotransposons in the wheat genome. Seven families were identified on the basis of the nucleotide sequence similarities of the domain. These families are common to the genomes of ancestral diploid species of wheat, evidence that they were established prior to diploid speciation, and their presence in barley and rice was suggested. Recent activity of some of the families was inferred in wheat on the basis of data that included synonymous and nonsynonymous nucleotide substitution rates in the reverse transcriptase domain.

Cloning, Molecular↗
PubMed2007

Effect of compounds released during pretreatment of wheat straw on microbial growth and enzymatic hydrolysis rates.

In the process of producing ethanol from lignocellulosic materials such as wheat straw, compounds that can act inhibitory to enzymatic hydrolysis and to cellular growth may be generated during the pretreatment. Ethanol production was evaluated on pretreated wheat straw hydrolysate using four different recombinant Saccharomyces cerevisiae strains, CPB.CR4, CPB.CB4, F12, and FLX. The fermentation performance of the four S. cerevisiae strains was tested in hydrolysate of wheat straw that has been pretreated at high dry matter content (220 g/L dry matter). The results clearly showed that F12 was the most robust strain, whereas the other three strains were strongly inhibited when the fraction of hydrolysate in the fermentation medium was higher than 60% (v/v). Furthermore, the impact of different lignin derivatives commonly found in the hydrolysate of pretreated wheat straw, was tested on two different enzyme mixtures, a mixture of Celluclast 1.5 L FG and Novozym 188 (3:1) and one crude enzyme preparation produced from Penicillium brasilianum IBT 20888. From all the potential inhibiting compounds that were tested, formic acid had the most severe influence on the hydrolysis rate resulting in a complete inactivation of the two enzyme mixtures.

Ethanol↗
PubMed1986

[Bronchopneumopathy caused by wheat flour: analysis of clinical cases].

We studied 31 subjects exposed to wheat (mean work duration: 33 years) with chronic bronchopulmonary disease. 19 subjects complained of chronic cough and phlegm, 5 of symptoms of bronchoconstriction not associated to chronic cough and phlegm; 7 subjects complained of oculo-rhinitis. Subjects with symptoms of bronchoconstriction had a longer mean age and work duration than the other ones. Pulmonary function tests showed a slight decrease of mid-expiratory flow rate with respect to reference values. Skin reactivity to common allergens and to allergenic extracts of wheat flour and grain was low, but a relevant number of dubious responses (weal: 3-4 mm) to specific allergens was observed. Bronchial hyperresponsiveness to methacholine or bethanechol was observed in 17 out of 30 subjects, and a positive response to occupational-type specific bronchial provocative test (sBPT) was elicited in 10 out of 30 subjects. There was a low relationship between positive response to sBPT and symptoms of bronchoconstriction or skin reactivity to specific allergens. These observations suggest that a high prevalence of chronic bronchitis and/or chronic airway limitation is showed in workers long-term exposed to wheat flour, in front of a low prevalence of skin reactivity to flour and grain. Occupational-type sBPT might induce in these patients a non immunological positive response to wheat flour by means of a not completely known mechanism.

Adult↗
PubMed1984

Pronounced structural similarities between the small subunit ribosomal RNA genes of wheat mitochondria and Escherichia coli.

We present here the nucleotide sequence of the small subunit (18S) rRNA gene from wheat mitochondria. Aside from five discrete variable domains, this gene and the analogous (16S) rRNA gene in Escherichia coli show essentially a one-to-one correspondence in their potential secondary structures, with regions accounting for 86% of the bacterial 16S rRNA having a strict secondary structure counterpart in the mitochondrial 18S rRNA. Primary sequence identity between the two rRNAs ranges from 73% to 85% (76% overall) within regions of conserved secondary structure. Within a smaller secondary structure core common to all small subunit rRNAs, the wheat mitochondrial sequence shares substantially more primary sequence identity with the E. coli (eubacterial) sequence (88%) than with the small subunit rRNA sequences of Halobacterium volcanii (an archaebacterium) (71%) or Xenopus laevis cytoplasm (61%). Moreover, the wheat mitochondrial sequence contains a very high proportion of certain lineage-specific residues that distinguish eubacterial/plastid 16S rRNAs from archaebacterial 16S and eukaryotic cytoplasmic 18S rRNAs. These data establish that the ancestry of the wheat mitochondrial 18S rRNA gene can be traced directly and specifically to the eubacterial primary kingdom, and the data provide compelling support for a relatively recent xenogenous (endosymbiotic) origin of plant mitochondria from eubacteria-like organisms.

Base Sequence↗
PubMed2000

An enzyme linked immunoassay for the determination of deoxynivalenol in wheat based on chicken egg yolk antibodies.

An indirect competitive enzyme linked immunoassay (ELISA) for the detection of the Fusarium mycotoxin deoxynivalenol (DON) in wheat was developed. Instead of the much more common antibody isolation from mammal serum, DON specific antibodies were, for the first time, isolated from the eggs of previously immunized hens. The limit of detection was 2 microg/L for standard curves and spiked wheat extracts. Recoveries for naturally contaminated samples (200-525 microg/kg) were between 80 and 125% compared with GC-ECD data. Concentrations for naturally contaminated samples were chosen with regard to current Austrian guidelines concerning DON levels in produce intended for human consumption, recommending a maximum of 500 microg DON/kg.

Animals↗
PubMed2005

Nonrandom distribution and frequencies of genomic and EST-derived microsatellite markers in rice, wheat, and barley.

BACKGROUND: Earlier comparative maps between the genomes of rice (Oryza sativa L.), barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.) were linkage maps based on cDNA-RFLP markers. The low number of polymorphic RFLP markers has limited the development of dense genetic maps in wheat and the number of available anchor points in comparative maps. Higher density comparative maps using PCR-based anchor markers are necessary to better estimate the conservation of colinearity among cereal genomes. The purposes of this study were to characterize the proportion of transcribed DNA sequences containing simple sequence repeats (SSR or microsatellites) by length and motif for wheat, barley and rice and to determine in-silico rice genome locations for primer sets developed for wheat and barley Expressed Sequence Tags. RESULTS: The proportions of SSR types (di-, tri-, tetra-, and penta-nucleotide repeats) and motifs varied with the length of the SSRs within and among the three species, with trinucleotide SSRs being the most frequent. Distributions of genomic microsatellites (gSSRs), EST-derived microsatellites (EST-SSRs), and transcribed regions in the contiguous sequence of rice chromosome 1 were highly correlated. More than 13,000 primer pairs were developed for use by the cereal research community as potential markers in wheat, barley and rice. CONCLUSION: Trinucleotide SSRs were the most common type in each of the species; however, the relative proportions of SSR types and motifs differed among rice, wheat, and barley. Genomic microsatellites were found to be primarily located in gene-rich regions of the rice genome. Microsatellite markers derived from the use of non-redundant EST-SSRs are an economic and efficient alternative to RFLP for comparative mapping in cereals.

Amino Acid Motifs↗
PubMed1990

Two Closely Related Wheat Storage Proteins Follow a Markedly Different Subcellular Route in Xenopus laevis Oocytes.

[alpha]-Gliadins and [gamma]-gliadins are two closely related wheat storage proteins that evolved from a common ancestral gene. However, synthesis of [alpha]-gliadins and [gamma]-gliadins in Xenopus laevis oocytes revealed striking differences in their subcellular routing. The major portion of [alpha]-gliadin accumulated inside the oocyte, whereas most of the [gamma]-gliadin was secreted. Disruption of the Golgi apparatus by monensin revealed that the major part of secretion of [gamma]-gliadin is Golgi mediated. The difference in the subcellular route between [alpha]-gliadin and [gamma]-gliadin may be attributed to differential transport from the endoplasmic reticulum to the Golgi apparatus, a process that is generally the rate-limiting step in protein secretion. Coinjection of the two mRNAs had no effect on their routing, indicating no interaction between them. Our results support the hypothesis that subcellular transport of gliadins in wheat endosperm occurs in two separate routes; one is Golgi mediated, and the other is not. We also show that the subcellular transport may be markedly affected by small structural variations within closely related storage proteins.

Journal Article↗
PubMed2004

Coeliac disease in Middle Eastern countries: a challenge for the evolutionary history of this complex disorder?

About 10,000 years ago domestication and farming of wheat and other cereals developed in the 'Fertile Crescent', an area including modern Turkey, Iraq and Iran. Agriculture then slowly spread from Middle East to Europe. Coeliac disease is the permanent intolerance to dietary gluten, the major protein component of wheat. It has been until relatively recently hypothesised that wheat consumption exerted a negative selective pressure on genes predisposing to coeliac disease, eventually leading to higher coeliac disease frequency in Northeastern Europe because of lack of exposure to cereals. This theory is at variance with recent studies showing that coeliac disease is as common in Middle Eastern countries as in Europe. High prevalence of coeliac disease has been found in Iran, in both the general population and at-risk groups, e.g. patients with irritable bowel syndrome or type 1 diabetes. Clinical manifestations of coeliac disease vary markedly with the age of the patient, the duration and the extent of disease. Clinical studies showed that presentation with non-specific symptoms or no symptoms is as common in the Middle East as in Europe. Wheat represented a major component of the Iranian diet for many centuries and it may be argued that the continuous and high level of exposure to wheat proteins has induced some degree of immune tolerance, leading to milder symptoms that may be misdiagnosed as irritable bowel syndrome or unexplained gastrointestinal disorders. The gluten-free diet represents a real challenge to both patients and clinicians in this area. This is particularly difficult in the absence of any supply for gluten-free diet in Middle Eastern countries.

Celiac Disease↗