176
|
Wan Y, Yan Z, Liu K, Zheng Y, D'Ovidio R, Shewry PR, Halford NG, Wang D. Comparative analysis of the D genome-encoded high-molecular weight subunits of glutenin. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2005; 111:1183-90. [PMID: 16177903 DOI: 10.1007/s00122-005-0051-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2005] [Accepted: 07/12/2005] [Indexed: 05/04/2023]
Abstract
Four genes encoding novel 1Dx-type high-molecular weight (HMW) subunits were amplified by polymerase chain reaction, two each from Aegilops tauschii and bread wheat Triticum aestivum. The two subunits from Ae. tauschii (1Dx2.1(t) and 1Dx2(t)) were both very similar in sequence to subunit 1Dx2 from bread wheat. In contrast, the two novel bread wheat subunits (1Dx2.2 and 1Dx2.2*) differed from subunit 1Dx2 in having different internally duplicated regions (of 132 and 186 amino acid, respectively) within their repetitive domains. These duplicated sequences were located adjacent to the regions from which they had been duplicated and had complete intact repeat motifs at each end. The implications of these results for HMW subunit evolution and wheat quality improvement are discussed.
Collapse
|
177
|
Terzi V, Morcia C, Gorrini A, Stanca AM, Shewry PR, Faccioli P. DNA-based methods for identification and quantification of small grain cereal mixtures and fingerprinting of varieties. J Cereal Sci 2005. [DOI: 10.1016/j.jcs.2004.08.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
178
|
Chamba EB, Halford NG, Forsyth J, Wilkinson M, Shewry PR. Molecular cloning of β-kafirin, a methionine-rich protein of sorghum grain. J Cereal Sci 2005. [DOI: 10.1016/j.jcs.2004.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
179
|
Forsyth JL, Beaudoin F, Halford NG, Sessions RB, Clarke AR, Shewry PR. Design, expression and characterisation of lysine-rich forms of the barley seed protein CI-2. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2005; 1747:221-7. [PMID: 15698957 DOI: 10.1016/j.bbapap.2004.11.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2004] [Revised: 10/26/2004] [Accepted: 11/16/2004] [Indexed: 11/18/2022]
Abstract
Chymotrypsin inhibitor CI-2 is a small (84 residue) barley seed protein that has been used extensively to study protein folding. It also contains eight lysine residues, making it an attractive target for expression in transgenic plants to increase their lysine contents. We have designed three lysine-enriched forms of CI-2 and compared their structures and properties with that of the wild type protein. One mutant containing three additional lysine residues in the inhibitory loop shows high stability to denaturation and reduced inhibitory activity, indicating its suitability for use in genetic engineering.
Collapse
|
180
|
Mills ENC, Jenkins JA, Alcocer MJC, Shewry PR. Structural, biological, and evolutionary relationships of plant food allergens sensitizing via the gastrointestinal tract. Crit Rev Food Sci Nutr 2005; 44:379-407. [PMID: 15540651 DOI: 10.1080/10408690490489224] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The recently completed genome sequence of the model plant species Arabidopsis has been estimated to encode over 25,000 proteins, which, on the basis of their function, can be classified into structural and metabolic (the vast majority of plant proteins), protective proteins, which defend a plant against invasion by pathogens or feeding by pests, and storage proteins, which proved a nutrient store to support germination in seeds. It is now clear that almost all plant food allergens are either protective or storage proteins. It is also becoming evident that those proteins that trigger the development of an allergic response through the gastrointestinal tract belong primarily to two large protein superfamilies: (1) The cereal prolamin superfamily, comprising three major groups of plant food allergens, the 2S albumins, lipid transfer proteins, and cereal alpha-amylase/trypsin inhibitors, which have related structures, and are stable to thermal processing and proteolysis. They include major allergens from Brazil nut, peanuts, fruits, such as peaches, and cereals, such as rice and wheat; (2) The cupin superfamily, comprising the major globulin storage proteins from a number of plant species. The globulins have been found to be allergens in plant foods, such as peanuts, soya bean, and walnut; (3) The cyteine protease C1 family, comprising the papain-like proteases from microbes, plants, and animals. This family contains two notable allergens that sensitize via the GI tract, namely actinidin from kiwi fruit and the soybean allergen, Gly m Bd 30k/P34. This study describes the properties, structures, and evolutionary relationships of these protein families, the allergens that belong to them, and discusses them in relation to the role protein structure may play in determining protein allergenicity.
Collapse
|
181
|
Jenkins JA, Griffiths-Jones S, Shewry PR, Breiteneder H, Mills ENC. Structural relatedness of plant food allergens with specific reference to cross-reactive allergens: An in silico analysis. J Allergy Clin Immunol 2005; 115:163-70. [PMID: 15637564 DOI: 10.1016/j.jaci.2004.10.026] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND The body of sequence and structural information on allergens and the sequence analysis of whole plant genomes are facilitating the application of bioinformatic approaches to identifying and defining plant allergens. OBJECTIVE An in silico approach was used to quantify the distribution of plant food allergen sequences across protein families and to develop and apply a novel means of assessing conserved surface features important for IgE cross-reactivity. METHODS Plant food allergen sequences were classified into Pfam families on the basis of sequence homology. Contact surface areas of selected proteins were calculated with MOLMOL by using a 1.4-A probe, corrected by removing contributions from IgE inaccessible main chains and side chains forming the ligand binding sites. RESULTS A set of 129 food allergen sequences were classified into only 20 of 3849 possible Pfam families, with 4 families accounting for more than 65% of food allergens. Structural bioinformatic analysis of conserved exterior main chains and amino acid side chains in cross-reactive homologues of Bet v 1 and nonspecific lipid transfer proteins showed higher levels of similarity than shown by simple sequence comparisons. Thus, 75% of the Mal d 1 surface is likely to bind anti-Bet v 1 antibodies, compared with a sequence identity of approximately 56%. CONCLUSION Most plant food allergens belong to only 4 structural families, indicating that conserved structures and biological activities may play a role in determining or promoting allergenic properties. Structural bioinformatic analysis shows that conservation of 3-dimensional structure should be included in any assessment of potential IgE cross-reactivity in, for example, novel proteins.
Collapse
|
182
|
Terzi V, Pastori G, Shewry PR, Di Fonzo N, Michele Stanca A, Faccioli P. Real-time PCR-assisted selection of wheat plants transformed with HMW glutenin subunit genes. J Cereal Sci 2005. [DOI: 10.1016/j.jcs.2004.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
183
|
Wellner N, Mills ENC, Brownsey G, Wilson RH, Brown N, Freeman J, Halford NG, Shewry PR, Belton PS. Changes in Protein Secondary Structure during Gluten Deformation Studied by Dynamic Fourier Transform Infrared Spectroscopy. Biomacromolecules 2004; 6:255-61. [PMID: 15638528 DOI: 10.1021/bm049584d] [Citation(s) in RCA: 205] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Fourier transform infrared (FT-IR) spectroscopy was used to monitor changes in the secondary structure of wheat prolamins, the main components of gluten, during mechanical deformation in a series of cycles of extension and relaxation. A sample derived from protein bodies isolated from developing grain showed a buildup of persistent beta-sheet structure. In gluten, the ratio of beta-sheet to random and beta-turn structures changed on extension. After the applied force was released, the sample recovered some of its original shape and structure, but the material became stiffer in consecutive extension cycles. The relationship between gluten structure and mechanical properties is discussed in terms of a model in which conversion of beta-turn to beta-sheet structure is a response to extension and a means by which elastic energy is stored in the system.
Collapse
|
184
|
Konarev AV, Griffin J, Konechnaya GY, Shewry PR. The distribution of serine proteinase inhibitors in seeds of the Asteridae. PHYTOCHEMISTRY 2004; 65:3003-3020. [PMID: 15504435 DOI: 10.1016/j.phytochem.2004.08.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2004] [Revised: 07/21/2004] [Indexed: 05/24/2023]
Abstract
The Asteridae is one of the most successful clades of flowering plants comprising some 80,000 species. Despite this diversity, analysis of seeds from 398 species (representing 8 orders, 32 families and 181 genera) showed just two major types of serine proteinase inhibitors (PI). PIs of the potato inhibitor I family were widely distributed. These had M(r) of 7000-7500 and were inhibitory to subtilisin and one or more other proteinases (but only rarely elastase). The second major group was TI related to the well-characterised Bowman-Birk inhibitors of legume seeds but these varied widely in their sequences and structure. In addition to these two groups of inhibitors, seeds of the Solanaceae also often contained PI of the potato inhibitor II family while some other asterids contained inhibitors whose relationships were not established.
Collapse
|
185
|
Wilson ID, Barker GLA, Beswick RW, Shepherd SK, Lu C, Coghill JA, Edwards D, Owen P, Lyons R, Parker JS, Lenton JR, Holdsworth MJ, Shewry PR, Edwards KJ. A transcriptomics resource for wheat functional genomics. PLANT BIOTECHNOLOGY JOURNAL 2004; 2:495-506. [PMID: 17147622 DOI: 10.1111/j.1467-7652.2004.00096.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Grain development, germination and plant development under abiotic stresses are areas of biology that are of considerable interest to the cereal community. Within the Investigating Gene Function programme we have produced the resources required to investigate alterations in the transcriptome of hexaploid wheat during these developmental processes. We have single pass sequenced the cDNAs of between 700 and 1300 randomly picked clones from each of 35 cDNA libraries representing highly specific stages of grain and plant development. Annotated sequencing results have been stored in a publicly accessible, online database at http://www.cerealsdb.uk.net. Each of the tissue stages used has also been photographed in detail, resulting in a collection of high-quality micrograph images detailing wheat grain development. These images have been collated and annotated in order to produce a web site focused on wheat development (http://www.wheatbp.net/). We have also produced high-density microarrays of a publicly available wheat unigene set based on the 35 cDNA libraries and have completed a number of microarray experiments which validate their quality.
Collapse
|
186
|
Pantoja-Uceda D, Shewry PR, Bruix M, Tatham AS, Santoro J, Rico M. Solution structure of a methionine-rich 2S albumin from sunflower seeds: relationship to its allergenic and emulsifying properties. Biochemistry 2004; 43:6976-86. [PMID: 15170335 DOI: 10.1021/bi0496900] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The three-dimensional structure in aqueous solution of SFA-8, a 2S albumin 103-residue protein from seeds of sunflower (Helianthus anuus L.), has been determined by NMR methods. An almost complete (1)H resonance assignment was accomplished from analysis of two-dimensional (2D) COSY and 2D TOCSY spectra, and the structure was computed by using restrained molecular dynamics on the basis of 1393 upper limit distance constraints derived from NOE cross-correlation intensities measured in 2D NOESY spectra. In contrast with most other 2S albumins, SFA-8 consists of a single polypeptide chain without any cleavage in the segment of residues 30-46. The computed structures exhibited an rmsd radius of 0.52 A for the backbone structural core (residues 11-30 and 46-101) and 1.01 A for the side chain heavy atoms. The resulting structure consists of five amphipathic helices arranged in a right-handed superhelix, a folding motif first observed in nonspecific lipid transfer (nsLTP) proteins, and common to other 2S albumins. In contrast to nsLTP proteins, neither SFA-8 nor RicC3 (a 2S albumin from castor bean) has an internal cavity that is able to host a lipid molecule, which results from an exchange in the pairing of disulfide bridges in the CXC segment. Both 2S albumins and nonspecific lipid transfer proteins belong to the prolamin superfamily, which includes a number of important food allergens. Differences in the extension and solvent exposition of the so-called "hypervariable loop" (which connects helices III and IV) in SFA-8 and RicC3 may be responsible for the different allergenic properties of the two proteins. SFA-8 has been shown to form highly stable emulsions with oil/water mixtures. We propose that these properties may be determined partly by a hydrophobic patch at the surface of the protein which consists of five methionines that partially hide the Trp76 residue. The flexibility of the loop which contains Trp76 and the hydrophobicity of the whole environment may favor a conformational change, by which the Trp76 side chain may become inserted into the oil phase.
Collapse
|
187
|
Bekele E, Fido RJ, Tatham AS, Shewry PR. Heterogeneity and Polymorphism of Seed Proteins in Tef (Eragrotis Tef). Hereditas 2004. [DOI: 10.1111/j.1601-5223.1995.00067.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
|
188
|
Fido RJ, Mills ENC, Rigby NM, Shewry PR. Protein extraction from plant tissues. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2004; 244:21-7. [PMID: 14970539 DOI: 10.1385/1-59259-655-x:21] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
|
189
|
Tosi P, D'Ovidio R, Napier JA, Bekes F, Shewry PR. Expression of epitope-tagged LMW glutenin subunits in the starchy endosperm of transgenic wheat and their incorporation into glutenin polymers. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2004; 108:468-76. [PMID: 14574453 DOI: 10.1007/s00122-003-1459-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2003] [Accepted: 08/13/2003] [Indexed: 05/23/2023]
Abstract
The low-molecular-weight (LMW) glutenin subunits are components of the highly cross-linked glutenin polymers that confer viscoelastic properties to gluten and dough. They have both quantitative and qualitative effects on dough quality that may relate to differences in their ability to form the inter-chain disulphide bonds that stabilise the polymers. In order to determine the relationship between dough quality and the amounts and properties of the LMW subunits, we have transformed the pasta wheat cultivars Svevo and Ofanto with three genes encoding proteins, which differ in their numbers or positions of cysteine residues. The transgenes were delivered under control of the high-molecular-weight (HMW) subunit 1Dx5 gene promoter and terminator regions, and the encoded proteins were C-terminally tagged by the introduction of the c-myc epitope. Stable transformants were obtained with both cultivars, and the use of a specific antibody to the c-myc epitope tag allowed the transgene products to be readily detected in the complex mixture of LMW subunits. A range of transgene expression levels was observed. The addition of the epitope tag did not compromise the correct folding of the trangenic subunits and their incorporation into the glutenin polymers. Our results demonstrate that the ability to specifically epitope-tag LMW glutenin transgenes can greatly assist in the elucidation of their individual contributions to the functionality of the complex gluten system.
Collapse
|
190
|
Cunsolo V, Foti S, Saletti R, Gilbert S, Tatham AS, Shewry PR. Structural studies of the allelic wheat glutenin subunits 1Bx7 and 1Bx20 by matrix-assisted laser desorption/ionization mass spectrometry and high-performance liquid chromatography/electrospray ionization mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2004; 39:66-78. [PMID: 14760615 DOI: 10.1002/jms.558] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Structural studies of the high molecular mass (HMM) glutenin subunits 1Bx7 (from cvs Hereward and Galatea) and 1Bx20 (from cv. Bidi17) of bread wheat were conducted using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) and reversed-phase high-performance liquid chromatography/electrospray ionization mass spectrometry (RP-HPLC/ESI-MS). For all three proteins, MALDI-TOFMS analysis showed that the isolated fractions contained a second component with a mass about 650 Da lower than the major component. The testing and correction of the gene-derived amino acid sequences of the three proteins were performed by direct MALDI-TOFMS analysis of their tryptic peptide mixture. Analysis of the digest was performed by recording several MALDI mass spectra of the mixture at low, medium and high mass ranges, optimizing the matrix and the acquisition parameters for each mass range. Complementary data were obtained by RP-HPLC/ESI-MS analysis of the tryptic digest. This resulted in coverage of about 98% of the sequences. In contrast to the gene-derived data, the results obtained demonstrate the insertion of the sequence QPGQGQ between Trp716 and Gln717 of subunit 1Bx7 (cv. Galatea) and a possible single amino acid substitution within the T20 peptide of subunit 1Bx20. Moreover, the mass spectrometric data demonstrated that the lower mass components present in all the fractions correspond to the major components but lack about six amino acid residues, which are probably lost from the protein C-terminus. Finally, the results obtained provide evidence for the lack of glycosylation or other post-translational modifications of these subunits.
Collapse
|
191
|
|
192
|
|
193
|
|
194
|
|
195
|
|
196
|
Darlington H, Fido R, Tatham AS, Jones H, Salmon SE, Shewry PR. Milling and baking properties of field grown wheat expressing HMW subunit transgenes. J Cereal Sci 2003. [DOI: 10.1016/s0733-5210(03)00034-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
197
|
|
198
|
Feeney KA, Wellner N, Gilbert SM, Halford NG, Tatham AS, Shewry PR, Belton PS. Molecular structures and interactions of repetitive peptides based on wheat glutenin subunits depend on chain length. Biopolymers 2003; 72:123-31. [PMID: 12583015 DOI: 10.1002/bip.10298] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Synthetic and recombinant peptide models of the central repetitive domain of the high molecular weight subunits of wheat glutenin with different numbers of the consensus repeat motifs PGQGQQ + GYYPTSLQQ (21, 45, 110, and 203 residues long) and a recombinant 58,000-Da relative molecular mass (M(r) 58,000) repetitive peptide from a single subunit (1Dx5) are studied using Fourier transform IR spectroscopy. The spectra of the dry peptides are very similar; at low water contents (<76% relative humidity) there is an increase in beta-sheet structures in all peptides. However, on further hydration the content of beta sheets decrease and more beta turns are observed. The changes during the second step of hydration are very marked in the 21 and 45 residue peptides, but they are less apparent in the longer perfect repeat peptides. In the 110 and 203 residue peptides hydration results in increased contents of intermolecular beta-sheets and less beta-turn formation. In contrast, the beta-turn content of the M(r) 58,000 peptide increases during the second hydration step. The decreased extent of structure changes with increasing chain length indicates that cumulative intermolecular interactions, in particular hydrogen bonds, are an important factor in determining the structures in the solid state. The regularity of the perfect repeat sequences in the 21, 45, 110, and 203 residue peptides may favor the formation of larger stretches of intermolecular beta sheets. In contrast, the M(r) 58,000 peptide contains imperfect repeats (in common with native glutenin subunits), which may limit its ability to form intermolecular beta sheets.
Collapse
|
199
|
Abstract
A wide range of plants are grown for their edible tubers, but five species together account for almost 90 % of the total world production. These are potato (Solanum tuberosum), cassava (Manihot esculenta), sweet potato (Ipomoea batatus), yams (Dioscorea spp.) and taro (Colocasia, Cyrtosperma and Xanthosoma spp.). All of these, except cassava, contain groups of storage proteins, but these differ in the biological properties and evolutionary relationships. Thus, patatin from potato exhibits activity as an acylhydrolase and esterase, sporamin from sweet potato is an inhibitor of trypsin, and dioscorin from yam is a carbonic anhydrase. Both sporamin and dioscorin also exhibit antioxidant and radical scavenging activity. Taro differs from the other three crops in that it contains two major types of storage protein: a trypsin inhibitor related to sporamin and a mannose-binding lectin. These characteristics indicate that tuber storage proteins have evolved independently in different species, which contrasts with the highly conserved families of storage proteins present in seeds. Furthermore, all exhibit biological activities which could contribute to resistance to pests, pathogens or abiotic stresses, indicating that they may have dual roles in the tubers.
Collapse
|
200
|
Sayanova OV, Beaudoin F, Michaelson LV, Shewry PR, Napier JA. Identification of primula fatty acid delta 6-desaturases with n-3 substrate preferences. FEBS Lett 2003; 542:100-4. [PMID: 12729906 DOI: 10.1016/s0014-5793(03)00358-2] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Fatty acid Delta(6)-desaturation, the first committed step in C(20) polyunsaturated fatty acid biosynthesis, is generally considered not to discriminate between n-3 and n-6 substrates. We previously identified higher plant species that showed preferential Delta(6)-desaturation of n-3 C(18) fatty acid substrates. A polymerase chain reaction-based approach was used to isolate 'front-end' cytochrome b(5) fusion desaturases from Primula vialii Franchet and Primula farinosa L. Functional analysis in Saccharomyces cerevisiae identified fatty acid Delta(6)-desaturases with a strong specificity for the n-3 substrate alpha-linolenic acid (18:3 Delta(9,12,15)). These results indicate that the accumulation of octadecatetraenoic acid (18:4 Delta(6,9,12,15)) in planta is due to the activity of a novel n-3-specific fatty acid Delta(6)-desaturase.
Collapse
|