DOCSLIB.ORG

Celiac Disease Among Children and Adolescents

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Celiac Disease Among Children and Adolescents Celiac Disease Among Children and Adolescents M. Luisa Mearin, MD, PhD eliac disease (CD) is a chronic disorder caused for the disease. However, the relationship between by an inflammatory T-cell response to the gluten ingestion and the symptoms of CD was discov- C storage proteins in wheat (gliadin), rye (seca- ered by the Dutch pediatrician Willem-Karel Dicke lin), and barley (hordein), which are collectively called (1905-1962).4 He became the medical director of the “gluten” and characterized by the presence of typical Juliana Children’s Hospital in The Hague (The Neth- autoantibodies and histological alterations of the small erlands) at the age of 31. Long before the start of the bowel mucosa. Genetic, immunological, and environ- Second World War (1934-1936) he started experi- mental factors are necessary for the expression of the ments with wheat-free diets. At the end of World War disease. Ingestion of gluten by genetically predisposed II, during the 1944-1945 winter of starvation, the people precipitates an uncontrolled T-cell-driven in- delivery of normal food such as bread to his young flammatory response that leads to disruption of the patients in his hospital was endangered. This period structural and functional integrity of the small bowel and dietary studies convinced him even more that mucosa. CD is treated with a gluten-free diet (GFD), eating less cereals and more uncommon food products which leads to resolution of the clinical disease and such as tulip bulbs improved the clinical condition of restoration of the histological abnormalities. CD was his patients and that a wheat-free diet had favorable once thought to be a rare condition, but at the present effects on children with CD. After World War II, in time it is accepted that CD is the most common form collaboration with Van de Kamer, a biochemist from of food hypersensitivity in children and adults. the Netherlands’ Central Institute for Nutritional Re- The first description of CD is attributed to Aretaeus search TNO in Utrecht, and with Weyers, a pediatri- the Cappadocian, who lived in the second century cian from the Wilhelmina Children’s Hospital in 1 AD. He noted the characteristic stool and chronic Utrecht, he extended his research and demonstrated nature of the condition and observed that children that gliadins, ie, the alcohol-soluble fractions of gluten could also be affected by the disease. In 1888, Samuel (wheat protein), produced fat malabsorption in pa- Gee, a physician working at the St. Bartholomew tients with CD.5 His experiences with the wheat-free Hospital in London, provided a thorough description diet were at first published in “Het Nederlands Tijd- 2 of the clinical features of childhood CD. During the schrift voor Geneeskunde” (Dutch Journal of Medi- first half of the past century, it was generally agreed cine) in 1941.6 In his PhD dissertation, published in that the treatment for CD was rest and diet. In 1924 1950, he described a dietary study over a period of Sidney Haas described his treatment of childhood CD several years at the Juliana Children’s Hospital in 3 with a banana diet, but there was hardly any form of patients with CD.7 In his PhD thesis Dicke wrote: diet not frequently discussed at that time as a treatment “The starting point of this treatment (gluten-free diet) was to me an observation of M.E. van Dusseldorp and H. A. Stheemann, during the treatment of a celiac From the Department of Pediatrics, Leiden University Medical Center patient” (chapter 3: treatment with a diet free of corn). and Free University Medical Center, Amsterdam, The Netherlands. Dicke refers to a child with CD who went through The author has no commercial interest in the subject and no financial relationships or other relationships that would contribute to a conflict three attacks of “gastrointestinal catarrh” after eating of interest. corn-containing products during a stay in the hospital. Curr Probl Pediatr Adolesc Health Care 2007;37:86-105 This observation was presented by Dr. Stheemann (the 1538-5442/$ - see front matter © 2007 Mosby, Inc. All rights reserved. supervisor of Dicke in The Hague) in The Medical doi:10.1016/j.cppeds.2007.01.001 Society of The Hague in 1932. Van Dusseldorp would 86 Curr Probl Pediatr Adolesc Health Care, March 2007 succeed Dicke as one of the first women directors of a children with CD do not have malabsorption and the Hospital in The Netherlands. clinical picture at presentation is very variable. Not all A few years after Dicke’s discovery, the advent of CD patients are equal. While some develop CD very the peroral intestinal mucosal biopsy led to confirma- early in life, others may eat gluten for many years tion of the characteristic intestinal histopathology of before the disease becomes apparent. The clinical CD.8 picture of CD is very heterogeneous with a broad spectrum of symptoms, from malabsorption, chronic diarrhea, and failure to thrive (the classic “triad”) to Clinical Spectrum and the Iceberg of abdominal pain, lassitude, iron-deficiency anemia, de- CD layed puberty, nonspecific arthritis, depression, ataxia, low bone mineral density, or dental enamel hypoplasia CD occurs largely in Caucasians. The disease has without gastrointestinal complaints.11,20 This hetero- been well documented in Asians from India, Pakistan, geneity in the clinical presentation is one of the causes and Iran,9 but it is rare or nonexistent among native of poor diagnosis of the disease. At present it is not Africans, Japanese, and Chinese. Using simple sero- known what causes these differences in the clinical logical tests, it has gradually become clear that the expression of CD, but there is some evidence that both prevalence of CD in different countries in the Middle genetic and environmental factors may be in- East, North Africa, and India where wheat has been volved.21,22 The relationship between the different the major staple food for many centuries is almost the HLA-DR and -DQ haplotypes of the children with CD same as that in Western countries. Clinical studies and their clinical presentation has been thoroughly showed that presentation with nonspecific symptoms investigated. Some researchers have found a signifi- or no symptoms is as common in the Middle East as it cant relationship between the gene dose effect and the is in Europe. A high index of suspicion for CD should heterogeneity of the clinical disease,21-23 but others be maintained in all developing countries for patients have not noted an association.24 Congia and cowork- who present with chronic diarrhea or iron-deficiency ers22 found that a double dose of DQ2 (␣1*0501, anemia.10 ␤1*0201) predisposes for an early onset and more CD is a common, but frequently unrecognized, severe disease manifestations. The differences in out- disease. The disease is more frequent among females, come can be partially explained by the fact that, for with a female-to-male ratio of 2-3:1. Screening studies statistical analysis in this latter study, the groups were have shown that CD is severely underdiagnosed, with divided in double-, single-, or no-dose HLA-DQ2, and a prevalence of 0.5 to 1% among the white popula- the authors also limited the phenotypic distribution to tion,11 both in adults12,13 and in children.14-16 Assum- fully expressed disease versus mono-/oligosymptom- ing a conservative prevalence of 0.5%, this corre- atic. We have recently shown that children with the sponds to about 2.5 million CD cases in Europe. DR3DQ2-DR5DQ7 and DR5DQ7-DR7DQ2 genotype Approximately 85% of these cases are unrecognized are presented with CD at an earlier age and have a and thus also untreated. Findings from mass screening more severe clinical picture, which suggests a link studies in the USA show a prevalence of the disease between the genotype and phenotype. A correlation similar to that reported in Europe and suggest that CD between disease severity and the HLA-DQ2 gene dose is a much greater problem in the United States than has was not observed (Vermeulen B, Hogen Esch C, previously been appreciated.17 CD is also a frequent Yuksel Z, et al., unpublished data). It is possible that condition in South America, as shown by the preva- other, non-HLA genetic factors also play a role in the lence of undiagnosed CD of 1:681 among apparently different phenotypic expression of CD. healthy blood donors in Brazil18 and of 1:167 among The iceberg is a model frequently used to explain the the general urban population in Argentina, presenting clinical spectrum of CD (Fig 1). with a heterogeneous clinical picture and a predomi- nance of asymptomatic cases.19 ● The tip of the iceberg is formed by the children CD is frequently unrecognized by physicians, in part with clinically diagnosed CD, among others, because of its variable clinical presentation and symp- those with clear gastrointestinal symptoms such toms.20 CD is easily diagnosed in children with a as chronic diarrhea and malabsorption (Table 1), symptomatic malabsorption syndrome, but most of the those with so-called “classic CD.” The symptoms Curr Probl Pediatr Adolesc Health Care, March 2007 87 FIG 2. Frequency of diagnosis of childhood celiac disease in the Netherlands. FIG 1. The iceberg of celiac disease. ● In the Netherlands, as in most countries, the major- TABLE 1. Some clinical manifestations of celiac disease in children ity of CD diagnoses are in children with the and adolescents System Manifestation (Possible) Cause “classic” symptoms. However, the results of a prospective national study of all the newly diag- Gastrointestinal Diarrhea Atrophy of the small Distended abdomen bowel mucosa nosed cases of CD throughout the country from Vomiting Malabsorption 1993 to 2000 show that the recognition of childhood Anorexia CD in the Netherlands has increased significantly Weight loss 20 Failure to thrive during the last few years (Fig 2), and that the Aphthous stomatitis clinical picture has changed as well with a decrease Hematology Anemia Iron malabsorption in the frequency of “classic” symptoms (Fig 3).
Load more

Recommended publications
  • Celiac Disease: It's Autoimmune Not an Allergy
    CELIAC DISEASE: IT’S AUTOIMMUNE NOT AN ALLERGY! Analissa Drummond PA-C Department of Pediatrics Division of Pediatric Gastroenterology HISTORY OF CELIAC DISEASE Also called gluten-sensitive enteropathy and nontropical spue First described by Dr. Samuel Gee in a 1888 report entitled “On the Coeliac Affection” Term “coeliac” derived from Greek word koiliakaos-abdominal Similar description of a chronic, malabsorptive disorder by Aretaeus from Cappadochia ( now Turkey) reaches as far back as the second century AD HISTORY CONTINUED The cause of celiac disease was unexplained until 1950 when the Dutch pediatrician Willem K Dicke recognized an association between the consumption of bread, cereals and relapsing diarrhea. This observation was corroborated when, during periods of food shortage in the Second World War, the symptoms of patients improved once bread was replaced by unconventional, non cereal containing foods. This finding confirmed the usefulness of earlier empirical diets that used pure fruit, potatoes, banana, milk, or meat. HISTORY CONTINUED After the war bread was reintroduced. Dicke and Van de Kamer began controlled experiments by exposing children with celiac disease to defined diets. They then determined fecal weight and fecal fat as a measure of malabsorption. They found that wheat, rye, barley and to a lesser degree oats, triggered malabsorption, which could be reversed after exclusion of the “toxic” cereals from the diet. Shortly after, the toxic agents were found to be present in gluten, the alcohol-soluble fraction of wheat protein. PATHOPHYSIOLOGY Celiac disease is a multifactorial, autoimmune disorder that occurs in genetically susceptible individuals. Trigger is an environmental agent-gliadin component of gluten.
    [Show full text]
  • Rebuilding Gluten Network of Damaged Wheat by Mean Of
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Digital.CSIC REBUILDING GLUTEN NETWORK OF DAMAGED WHEAT BY MEAN OF 2 GLUCOSE OXIDASE TREATMENT 4 A. Bonet1, C.M. Rosell1a, I. Pérez-Munuera2, I. Hernando2, 6 1 Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC). PO Box 73. Burjassot-46100. Valencia. Spain 8 2 Departamento de Tecnología de Alimentos, Universidad Politécnica de Valencia, P.O. 10 Box. 22012, 46071, Valencia, Spain. 12 a To whom correspondence should be addressed. E-mail: [email protected] 14 Running title : Glucose oxidase effect on insect damaged gluten 16 - 1 - ABSTRACT 2 The disrupted gluten structure of infested wheat flours yields to low quality doughs unusable to bread-making processes. Enzymes are replacing chemical treatments in 4 the food industry as a tool to treat weak flours. Glucose oxidase (GO) is one of the most promising oxidative enzymes although it has not been demonstrated yet its 6 efficiency over the alcohol-soluble fraction of the gluten proteins. If this enzyme could restore the broken covalent bonds between the glutenin subunits, the gluten network of 8 damaged wheat flour would recover their native structure and functionality. This treatment would allow bakers to use damaged flour, reducing the economical losses 10 produced by this plague around Europe and North Africa. Electrophoretic studies demonstrated the formation of high molecular weight aggregates in the glutenin 12 fraction, which had a characteristic thermal stability depending on the enzyme dosage. Those molecular studies agreed with the bread-making assays made with the 14 maximum enzyme dosage and the microstructure determination.
    [Show full text]
  • Properties of Proteins Contributing to Functionality of Cereal Foods 1
    Purchased by U.S. Department of Agriculture for Official Use. Reprinted from CEREAL FOODS WORLD, July 1979, Volume 24, No.7 Published by the American Association of Cereal Chemists, Inc. 3340 Pilot Knob Road, St. Paul, Minnesota 55121 Printed in the U.S.A. Properties of Proteins Contributing to Functionality of Cereal Foods 1 J. S. Wall, Northern Regional Research Center, Science and Educational Administration, Agricultural Research, U.S. Department of Agriculture,z Peoria, IL 61604 The functional properties of proteins in foods, including emulsifier. This versatility reflects the fact that the 21 amino those in cereal products, are determined by the molecular acids have different side chains tied together in varied sequences composition and structure of the individual proteins and their and amounts. One protein may contain groups that form interactions with one another and with other substances. associations with polar substances and groups that favor a Improving or modifying food characteristics such as viscosity, nonpolar environment. texture, water absorption, or fat emulsification may involve altering the constituent proteins or adding other proteins. Excellent reviews and symposia have related many aspects of TABLE I. Functional Properties of Proteins in Foods the chemistry of proteins to their contributions to the stability and Their Applications and organoleptic properties offoods (1-3). However, use ofnew Property Applications techniques such as amino acid sequence analysis, x-ray Emulsification Meats, coffee whiteners. salad dressings crystallography, and NM R in the study ofprotein structure and Hydration Doughs. meats physical properties is advancing our concepts of the roles of Viscosity Beverages, doughs proteins in food processing, structure, and acceptability.
    [Show full text]
  • And Modern Wheat Species (Durum and Common Wheat)
    foods Article Comparative Study on Gluten Protein Composition of Ancient (Einkorn, Emmer and Spelt) and Modern Wheat Species (Durum and Common Wheat) Sabrina Geisslitz 1, C. Friedrich H. Longin 2, Katharina A. Scherf 1,3,* and Peter Koehler 4 1 Leibniz-Institute for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Strasse 34, 85354 Freising, Germany 2 State Plant Breeding Institute, University of Hohenheim, Fruwirthstraße 21, 70599 Stuttgart, Germany 3 Department of Bioactive and Functional Food Chemistry, Institute of Applied Biosciences, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131 Karlsruhe, Germany 4 biotask AG, Schelztorstrasse 54-56, 73728 Esslingen am Neckar, Germany * Correspondence: [email protected] Received: 16 August 2019; Accepted: 6 September 2019; Published: 12 September 2019 Abstract: The spectrophotometric Bradford assay was adapted for the analysis of gluten protein contents (gliadins and glutenins) of spelt, durum wheat, emmer and einkorn. The assay was applied to a set of 300 samples, including 15 cultivars each of common wheat, spelt, durum wheat, emmer and einkorn cultivated at four locations in Germany in the same year. The total protein content was equally influenced by location and wheat species, however, gliadin, glutenin and gluten contents were influenced more strongly by wheat species than location. Einkorn, emmer and spelt had higher protein and gluten contents than common wheat at all four locations. However, common wheat had higher glutenin contents than einkorn, emmer and spelt resulting in increasing ratios of gliadins to glutenins from common wheat (< 3.8) to spelt, emmer and einkorn (up to 12.1). With the knowledge that glutenin contents are suitable predictors for high baking volume, cultivars of einkorn, emmer and spelt with good predicted baking performance were identified.
    [Show full text]
  • Wheat Improvement: the Truth Unveiled
    Wheat Improvement: The Truth Unveiled By The National Wheat Improvement Committee (NWIC) From wheat farmers to wheat scientists, we know consumers are yearning for more transparency and trust within their food “system.” We understand those concerns as consumers ourselves. In an effort to give consumers full scientific knowledge of how wheat has been improved over the years, we have worked together to publish a concise response to recent claims made by Dr. William Davis. The National Wheat Improvement Committee has compiled the following responses to Davis’ slander attack on wheat’s breeding and science improvements. Responses were developed with a scientific and historical perspective, utilizing references from peer-reviewed research and input from U.S. and international wheat scientists. Wheat Breeding & Science The wheat grown around the world today came from three grassy weed species that naturally hybridized around 10,000 years ago. The past 70 years of wheat breeding have essentially capitalized on the variation provided by wheat’s hybridization thousands of years ago and the natural mutations which occurred over the millennia as the wheat plant spread around the globe. There is no crop plant in the modern, developed world – from grass and garden flowers, to wheat and rice – that is the same as it first existed when the Earth was formed, nor is the environment the same. There is no mystery to wheat breeding. To breed new varieties, breeders employ two basic methods: Conventional crossing involves combining genes from complementary wheat plant parents to produce new genetic combinations (not new genes) in the offspring. This may account for slightly higher yield potential or disease and insect resistance relative to the parents.
    [Show full text]
  • Cellular Localization of Wheat High Molecular Weight Glutenin Subunits in Transgenic Rice Grain
    International Journal of Molecular Sciences Article Cellular Localization of Wheat High Molecular Weight Glutenin Subunits in Transgenic Rice Grain Yeong-Min Jo 1,†, Kyoungwon Cho 1,2,†, Hye-Jung Lee 1,3, Sun-Hyung Lim 1, Jin Sun Kim 1, Young-Mi Kim 1,* and Jong-Yeol Lee 1,* 1 National Institute of Agricultural Science, Rural Development Administration, Jeonju 54874, Korea; [email protected] (Y.-M.J.); [email protected] (K.C.); [email protected] (H.-J.L.); [email protected] (S.-H.L.); [email protected] (J.S.K.) 2 Department of Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea 3 Division of Life Science, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Korea * Correspondence: [email protected] (Y.-M.K.); [email protected] (J.-Y.L.); Tel.: +82-63-238-4601 (Y.-M.K.); +82-63-238-4616 (J.-Y.L.) † These authors contributed equally to this work. Received: 3 November 2017; Accepted: 15 November 2017; Published: 18 November 2017 Abstract: Rice (Oryza sativa L.) is a primary global food cereal. However, when compared to wheat, rice has poor food processing qualities. Dough that is made from rice flour has low viscoelasticity because rice seed lacks storage proteins that are comparable to gluten protein from wheat. Thus, current research efforts aim to improve rice flour processing qualities through the transgenic expression of viscoelastic proteins in rice seeds. In this study, we characterized the transgenic expression of wheat glutenin subunits in rice seeds. The two genes 1Dx5_KK and 1Dy10_JK, which both encode wheat high-molecular-weight glutenin subunits that confer high dough elasticity, were cloned from Korean wheat cultivars KeumKang and JoKyung, respectively.
    [Show full text]
  • Sequential Extraction and Quantitative Recovery of Gliadins, Glutenins, and Other Proteins from Small Samples of Wheat Flour
    J. Agric. Food Chem. 2005, 53, 1575−1584 1575 Sequential Extraction and Quantitative Recovery of Gliadins, Glutenins, and Other Proteins from Small Samples of Wheat Flour FRANCES M. DUPONT,* RONALD CHAN,ROCIO LOPEZ, AND WILLIAM H. VENSEL Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, 800 Buchanan Street, Albany, California 94710 Methods to sequentially extract and fractionate wheat flour proteins were evaluated to reliably quantify gliadins, glutenins, and albumins/globulins in single flour samples. Compositions of the resulting protein fractions were analyzed by RP-HPLC combined with SDS-PAGE. Unknown proteins were identified by mass spectrometry or N-terminal sequencing. The best separation and recovery of discrete albumin/ globulin, gliadin, and glutenin fractions from the same flour sample was achieved by extraction with 0.3 M NaI in 7.5% 1-propanol followed by 2% SDS, 25 mM DTT in 25 mM TRIS, pH 8.0, and precipitation of the solubilized proteins with ammonium acetate/methanol followed by acetone. Average flour composition for the variety Butte86 was 10% albumin/globulin, 40% gliadin, and 48% glutenin. This method should be useful for determining flour composition in diverse samples and evaluating relationships between proteins and end-use functionality. KEYWORDS: Albumin; flour; fractionation; glutenin; gliadin; HPLC; protein; quality; Triticum aestivum; wheat INTRODUCTION of total flour protein, amount and size range of glutenin polymer, After more than 250 years of research on the roles of proteins and proportions of glutenin subunits, gliadins, albumins, and in flour breadmaking quality, there is still a critical need for globulins (8, 11, 17-22).
    [Show full text]
  • Modeling to Understand Plant Protein Structure-Function Relationships—Implications for Seed Storage Proteins
    molecules Review Modeling to Understand Plant Protein Structure-Function Relationships—Implications for Seed Storage Proteins 1,2, 1, 2 1, Faiza Rasheed y, Joel Markgren y , Mikael Hedenqvist and Eva Johansson * 1 Department of Plant Breeding, The Swedish University of Agricultural Sciences, Box 101, SE-230 53 Alnarp, Sweden; [email protected] (F.R.); [email protected] (J.M.) 2 School of Chemical Science and Engineering, Fibre and Polymer Technology, KTH Royal Institute of Technology, SE–100 44 Stockholm, Sweden; [email protected] * Correspondence: [email protected] These authors contributed equally to this work. y Received: 2 January 2020; Accepted: 14 February 2020; Published: 17 February 2020 Abstract: Proteins are among the most important molecules on Earth. Their structure and aggregation behavior are key to their functionality in living organisms and in protein-rich products. Innovations, such as increased computer size and power, together with novel simulation tools have improved our understanding of protein structure-function relationships. This review focuses on various proteins present in plants and modeling tools that can be applied to better understand protein structures and their relationship to functionality, with particular emphasis on plant storage proteins. Modeling of plant proteins is increasing, but less than 9% of deposits in the Research Collaboratory for Structural Bioinformatics Protein Data Bank come from plant proteins. Although, similar tools are applied as in other proteins, modeling of plant proteins is lagging behind and innovative methods are rarely used. Molecular dynamics and molecular docking are commonly used to evaluate differences in forms or mutants, and the impact on functionality.
    [Show full text]
  • Could Global Intensification of Nitrogen Fertilisation Increase
    foods Perspective Could Global Intensification of Nitrogen Fertilisation Increase Immunogenic Proteins and Favour the Spread of Coeliac Pathology? Josep Penuelas 1,2,3,* , Albert Gargallo-Garriga 1,2,3 , Ivan A. Janssens 4, Philippe Ciais 5, Michael Obersteiner 6, Karel Klem 3 , Otmar Urban 3, Yong-Guan Zhu 7,8 and Jordi Sardans 1,2,3 1 CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra, 08193 Catalonia, Spain; [email protected] (A.G.-G.); [email protected] (J.S.) 2 CREAF, Cerdanyola del Valles, 08193 Catalonia, Spain 3 Global Change Research Institute, Czech Academy of Sciences, CZ-60300 Brno, Czech Republic; [email protected] (K.K.); [email protected] (O.U.) 4 Research Group Plants and Ecosystems (PLECO), Department of Biology, University of Antwerp, B-2610 Wilrijk, Belgium; [email protected] 5 Laboratory of Climate and Environmental Sciences, Institute Pierre Simon Laplace (PSL), 91191 Gif-sur-Yvette, France; [email protected] 6 Ecosystems Services and Management, International Institute for Applied Systems Analysis (IIASA), A-2361 Laxenburg, Austria; [email protected] 7 Key Laboratory of Urban Environment and Health, Chinese Academy of Sciences, Xiamen 361021, China; [email protected] 8 State Key Laboratory of Urban and Regional Ecology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China * Correspondence: [email protected] Received: 9 October 2020; Accepted: 2 November 2020; Published: 4 November 2020 Abstract: Fertilisation of cereal crops with nitrogen (N) has increased in the last five decades. In particular, the fertilisation of wheat crops increased by nearly one order of magnitude from 1961 to 1 1 2010, from 9.84 to 93.8 kg N ha− y− .
    [Show full text]
  • Structure of Glutenin : Achievements at the Northern Regional Research Center
    Ann. Technol., agric., I980, 29 (2), 249-277. 4909 Structure of glutenin : Achievements at the northern regional research center J. A. BIETZ and F. R. HUEBNER Northern Regional Research Center, A gricultural Research Science and Education Administration U.S. Department 01 Agriculture Peoria, Illinois 6I604 United States Summary The Northern Regional Research Center (~·RRC), Peoria, Illinois, is a laboratory of the U.S. Department of Agriculture's Science and Education Administration. For more than 20 years studies have been carried out on wheat glutel1 and its major fractions, gliadin and glutenin. This review summarizes studies of glutenin at ~ RRC and integrates this information with other laboratories' results to show how glutertirt structure relates to wheat's functional properties. In early studies at RRC, glutenin was isolated and shown to be a heterogeneous mixture of high molecular weight (.M:W) molecules containing ordered and unordered structures. Mole­ cules are asymmetric, and have high surface areas favoring interactions and association. Elec­ trophoresis showed that reduced glutenin contains many subunits joined by intermolecular disulfide bonds; hydrogen and hydrophobic bonds also contribute to glutenin's structure. Three distinct types of glutenin subunits were isolated and characterized, and genetic control of glu­ tenin's unique high MW subunits was established. Wheats having different qualities differ in subunit composition. Glutenin differs from low-MW gliadins, but its ethanol-soluble subunits are identical to subunits of high MW gliadin; a hypothesis was developed showing how different subunit types assemble into glutenin. High MW native glutenin molecules are related to wheat quality. These molecules are oriented by mixing, and form disulfide and noncovalent bonds with other flour proteins, resulting in a continuous gluten network in dough.
    [Show full text]
  • Highlights • the Potentiality of Using Soy Protein As Egg Replacers For
    *Highlights (for review) Highlights ñ The potentiality of using soy protein as egg replacers for cakes was evaluated. ñ Baking additives improved the physical quality of batter and eggless cakes. ñ Porous nanostructures in glutenin were important to the final quality of cakes. ñ Soy protein is a promising egg replacer with the aid of 1% mono, diglycerides. *Manuscript Click here to download Manuscript: FoodChem-R2.docx Click here to view linked References 1 Replacement of eggs with soybean protein isolates and 2 polysaccharides to prepare yellow cakes suitable for vegetarians 3 4 Muyang Lin a, b, Siang Hong Tay a, Hongshun Yang a, b, *, Bao Yang c, Hongliang Li d 5 6 a Food Science and Technology Programme, c/o Department of Chemistry, National 7 University of Singapore, Singapore 117543, Republic of Singapore 8 b National University of Singapore (Suzhou) Research Institute, 377 Lin Quan Street, 9 Suzhou Industrial Park, Suzhou, Jiangsu 215123, P. R. China 10 cKey Laboratory of Plant Resources Conservation and Sustainable Utilization, Guang 11 dong Provincial Key Laboratory of Applied Botany, South China Botanical Garde 12 n, Chinese Academy of Sciences, Guangzhou, Guangdong 510650, P. R. China 13 d Guangzhou Welbon Biological Technology Co., Ltd, Guangzhou Guangdong 14 510663, P. R. China 15 16 Running title: Replacement of eggs for preparing cakes 17 Contact information for corresponding authors (*) 18 Hongshun Yang, Ph.D., Assistant Professor 19 Food Science and Technology Programme, c/o Department of Chemistry, 20 National University
    [Show full text]
  • Effect of Extra Cysteine Residue of New Mutant 1Ax1 Subunit on The
    www.nature.com/scientificreports OPEN Effect of extra cysteine residue of new mutant 1Ax1 subunit on the functional properties of common Received: 17 February 2017 Accepted: 29 June 2017 wheat Published: xx xx xxxx Miao Li1, Yaqiong Wang1, Fengyun Ma1,2, Jian Zeng1, Junli Chang1, Mingjie Chen1, Kexiu Li1, Guangxiao Yang1, Yuesheng Wang1 & Guangyuan He1 Subunit pair 1Dx5 + 1Dy10 was recognized as superior subunit combination in wheat and contained an extra repetitive-domain cysteine residue in 1Dx5 that was important for understanding the formation of dough viscoelasticity. In this research, one specific serine codon of the1Ax1 gene corresponding to the extra cysteine residue of 1Dx5 was substituted by a cysteine codon through site-directed mutagenesis. Four homozygous transgenic lines (T4) expressing the mutant 1Ax1 gene (mut1Ax1) were produced. Their greater dough strength and stability were confirmed by mixograph and were associated with highly increased gluten index, larger amounts of gluten macropolymers, larger size distribution for glutenin macropolymer particles and varied sodium-dodecyl-sulfate sedimentation volumes, compared with those of the one line expressing wild 1Ax1 that had similar expression level of transgene. The contents of β-sheets in dough and disulfide groups in gluten of themut1Ax1 transgenic lines were significantly increased. The microstructure of dough mixed to peak showed a more continuous gluten matrix in the mutant transgenic lines than the one line mentioned-above. It was concluded that the extra cysteine residue of mutant 1Ax1 subunit plays a positive role in contributing to dough strength and stability of wheat by cross-linking into gluten aggregates through inter-chain disulfide bonds.
    [Show full text]