Chromosomal control of wheat endosperm proteins. A critical review.

Progress made in the chromosomal location of structural genes for wheat endosperm proteins, and in the study of the regulation and quantitative expression of these genes, by using aneuploids and by related techniques, is critically evaluated. Recommendations for future work are proposed

Differential effects of high-lysine mutations on the accumulation of individual members of a group of proteins encoded by a disperse multigene family in the endosperm of barley (Hordeum vulgare L.)

The CM proteins are a group of major salt-soluble endosperm proteins encoded by a disperse multigene family. The effects of high-lysine mutations on the net accumulation in barley endosperm of three members of this group (CMa, CMb, and CMe) have been investigated. Genes CMa, CMb and CMe are located in chromosomes 1, 4, and 3 respectively. Protein CMe has been found to be identical with a previously described trypsin inhibitor. The three proteins have been quantified in the different genetic stocks by HPLC. The different high-lysine mutations have different effects on the expression patterns of the three genes: CMe is markedly decreased and CMa and CMb are increased in mutant Risø 1508, whereas all three proteins are decreased in Risø 527 and increased in Risø 7 with respect to the wild-type Bomi; CMa and CMb are increased and CMe is unaffected in mutant Risø 56 with respect to the wild-type Carlsberg II; and protein CMe is markedly decreased in Hiproly barley as compared with its sister line CI4362. The implications of these results in connection with the evolution of CM proteins and with the characterization of high-lysine mutations are discusse

Chromosomal assignment of genes controlling salt-soluble proteins (albumins and globulins) in wheat and related species

alt-soluble proteins from the endosperms of wheat, barley, and rye have been separated by nonequilibrium electrofocusing x electrophoresis. Genes encoding 14 of the 25 components observed in wheat have been unambiguously assigned to 10 different chromosomes (1B, 3B, 3D, 4A, 4D, 5B, 6B, 6D, 7B, 7D) by analysis of the compensated nulli-tetrasomic series. Five more wheat proteins seem to be controlled by group 2 chromosomes. Analysis of wheat-barley and wheat-rye addition lines has led to the location of genes for 6 out of 20 barley proteins in 4 different chromosomes (1H, 3H, 4H, 6H; 1H is homoeologous to group 7 chromosomes of wheat) and of genes for 5 out of 20 rye proteins in two different chromosomes (2R, 4R). The relationship between the proteins reported here and previously characterized ones is discussed

New dimeric inhibitor of heterologous α-amylases encoded by a duplicated gene in the short arm of chromosome 3B of wheat (Triticum aestivum L.)

A new wheat dimeric α-amylase inhibitor, designated WDAI-3, has been characterized. WDAI-3 is a homodimeric protein active against α-amylase from human saliva and from the insect Tenebrio molitor, but inactive against that from pig pancreas or against trypsin. Its N-terminal amino acid sequence is closer to those of the wheat dimeric inhibitors 0.19 and 0.53 (89–91% identical positions in 44 residues) than to that of the monomeric 0.28 inhibitor (69% identical positions). Iha-BI-2, the gene encoding the new inhibitor, is located in the short arm of chromosome 3B, where it is part of an intrachromosomal gene duplication that also codes for the 0.53 inhibitor

Component-Resolved in Vitro Diagnosis in Peach-Allergic Patients

BACKGROUND: The in vitro diagnosis of pollen-related food allergy presents low specifi city and reproducibility with many conventional extracts. This can be improved using natural purifi ed allergens, recombinant purifi ed allergens, or both. OBJECTIVE: We compared specifi c immunoglobulin (Ig) E determination (sIgE), the basophil activation test (BAT), the histamine release test (HRT), and the cellular allergen stimulation test (CAST) using natural and recombinant allergens in the diagnosis of peach allergy. METHODS: Thirty-two peach allergic patients were studied. Skin prick tests were performed with commercial peach and extract with Mal d 1, nPru p 3, and profi lin (nPho d 2). sIgE, BAT, CAST, and HRT were determined using rPru p 3, rMal d 3, rBet v 1, rMal d 1, and rMal d 4. RESULTS: Agreement between the techniques was good with all the allergens, except HRT with rMal d 1 and rMal d 4. With rPru p 3, sIgE, CAST, BAT, and HRT showed sensitivity values of 88%, 81%, 72%, and 69% and specifi city values of 100%, 93%, 97%, and 83%, respectively. In patients with systemic symptoms or contact urticaria, the values were 100%, 85%, 81%, and 81%. In patients with oral allergy syndrome, sensitivity to profi lins or homologues of Bet v 1 was detected in 100% of the cases by all the techniques, except by HRT with rMal d 1, which detected 66% of the cases. CONCLUSIONS: The use of single allergens in the in vitro diagnosis of peach allergy by specifi c IgE determination, BAT, and CAST offers high specifi city and sensitivity, with better results than the HRT

Sensitization profiles to purified plant food allergens among pediatric patients with allergy to banana.

Banana fruit allergy is well known, but neither immunoglobulin E recognition patterns to purified plant food allergens nor true prevalences of putative banana allergens have been established. This study aimed to characterize β-1,3-glucanase and thaumatin-like protein (TLP) as banana allergens, testing them, together with other plant food allergens, in 51 children with allergic reactions after banana ingestion and both positive specific IgE and skin prick test (SPT) to banana. Banana β-1,3-glucanase and TLP were isolated and characterized. Both banana allergens, together with kiwifruit TLP Act d 2, avocado class I chitinase Pers a 1, palm pollen profilin Pho d 2 and peach fruit lipid transfer protein (LTP) Pru p 3, were tested by in vitro and in vivo assays. Banana β-1,3-glucanase (Mus a 5) was glycosylated, whereas banana TLP (Mus a 4) was not, in contrast with its homologous kiwi allergen Act d 2. Specific IgE to both banana allergens, as well as to peach Pru p 3, was found in over 70% of sera from banana-allergic children, and Mus a 4 and Pru p 3 provoked positive SPT responses in 6 of the 12 tested patients, whereas Mus a 5 in only one of them. Both peptidic epitopes and cross-reactive carbohydrate determinants were involved in the IgE-binding to Mus a 5, whereas cross-reactivity between Mus a 4 and Act d 2 was only based on common IgE protein epitopes. Profilin Pho d 2 elicited a relevant proportion of positive responses on in vitro (41%) and in vivo (58%) tests. Therefore, Mus a 4 and LTP behave as major banana allergens in the study population, and profilin seems to be also a relevant allergen. Mus a 5 is an equivocal allergenic protein, showing high IgE-binding to its attached complex glycan, and low in vivo potency

Evolutionary implications of sequential homologies among members of the trypsin/a-amylase inhibitors family (CM-proteins) in wheat and barley

The N-terminal amino acid sequence of four members of the trypsin/α-amylase inhibitor family in wheat, CM1, CM2, CM16 and CM17, has been investigated for 27–29 cycles by automated sequencing procedure. None of the proteins showed inhibitory activity against trypsin or α-amylases from different sources. The N-terminal sequences of these four proteins present a high degree of homology to each other as well as to those reported for other members of the same family in wheat and barley. Such homology is higher between a given protein and a second one associated with a different genome than between that protein and any other encoded in the same genome, indicating that most of the dispersion of the corresponding multi-gene family over several chromosomes took place before the wheat/barley evolutionary branching-ou

Component-resolved diagnosis of pollen allergy based on skin testing with profilin, polcalcin and lipid transfer protein pan-allergens

BACKGROUND Allergy diagnosis needs to be improved in patients suffering from pollen polysensitization due to the existence of possible confounding factors in this type of patients. OBJECTIVE To evaluate new diagnostic strategies by comparing skin responses to pan-allergens and conventional allergenic extracts with specific IgE (sIgE) to purified allergen molecules. METHODS One thousand three hundred and twenty-nine pollen-allergic patients were diagnosed by a combination of an in vitro method with a panel of 13 purified allergens, including major allergens and pan-allergens, using a high-capacity screening technology (ADVIA-Centaur®) and skin prick test (SPT) to pan-allergens and conventional extracts. RESULTS There was a high concordance (κ index) between in vitro (sIgE to major allergens) and in vivo (SPT to conventional extracts) methods in patients who were not sensitized to pan-allergens, but SPT with conventional extracts failed to diagnose patients with sensitization to pan-allergens. In patients who were simultaneously sensitized to polcalcins and profilins, there was a duplication both in the number of sensitizations to major allergens and in the years of disease evolution. There was a statistical association between sensitization to profilins and/or lipid transfer proteins and food allergy (P<0.0001). CONCLUSION The novel diagnostic strategy has proven to be a valuable tool in daily clinical practice. Introduction of routine SPT to pan-allergens is a simple and feasible way of improving diagnostic efficacy. Patients sensitized to pan-allergens should be tested by an adequate panel of allergenic molecules in order to identify the allergens that are responsible for the allergic disease

Mimotope mapping as a complementary strategy to define allergen IgE-epitopes: peach Pru p 3 allergen as a model.

Lipid transfer proteins (LTPs) are the major allergens of Rosaceae fruits in the Mediterranean area. Pru p 3, the LTP and major allergen of peach, is a suitable model for studying food allergy and amino acid sequences related with its IgE-binding capacity. In this work, we sought to map IgE mimotopes on the structure of Pru p 3, using the combination of a random peptide phage display library and a three-dimensional modelling approach. Pru p 3-specific IgE was purified from 2 different pools of sera from peach allergic patients grouped by symptoms (OAS-pool or SYS-pool), and used for screening of a random dodecapeptide phage display library. Positive clones were further confirmed by ELISA assays testing individual sera from each pool. Three-dimensional modelling allowed location of mimotopes based on analysis of electrostatic properties and solvent exposure of the Pru p 3 surface. Twenty-one phage clones were selected using Pru p 3-specific IgE, 9 of which were chosen using OAS-specific IgE while the other 12 were selected with systemic-specific IgE. Peptide alignments revealed consensus sequences for each pool: L37 R39 T40 P42 D43 R44 A46 P70 S76 P78 Y79 for OAS-IgE, and N35 N36 L37 R39 T40 D43 A46 S76 I77 P78 for systemic-IgE. These 2 consensus sequences were mapped on the same surface of Pru p 3, corresponding to the helix 2-loop-helix 3 region and part of the non-structured C-terminal coil. Thus, 2 relevant conformational IgE-binding regions of Pru p 3 were identified using a random peptide phage display library. Mimotopes can be used to study the interaction between allergens and IgE, and to accelerate the process to design new vaccines and new immunotherapy strategie

A dimeric inhibitor of insect a-amylase from barley. Cloning of the cDNA and identification of the protein

A cDNA clone, designated pUP-44, whose longest open reading frame codes for a protein that is homologous to the wheat α-amylase inhibitors, has been isolated from a library obtained from developing barley endosperm. The deduced sequence for the mature protein, which is 122 residues long, is preceded by a sequence of 30 residues which has the typical features of a signal peptide. A closely corresponding protein, designated BDAI-1, has been isolated from mature endosperm. BDAI-1 behaves as a dimer and inhibits the α-amylase from the insect Tenebrio molitor at concentrations that have no effect on salivary or pancreatic α-amylases