901
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Cartmell A, McKee LS, Peña MJ, Larsbrink J, Brumer H, Kaneko S, Ichinose H, Lewis RJ, Viksø-Nielsen A, Gilbert HJ, Marles-Wright J. The structure and function of an arabinan-specific alpha-1,2-arabinofuranosidase identified from screening the activities of bacterial GH43 glycoside hydrolases. J Biol Chem 2011; 286:15483-95. [PMID: 21339299 PMCID: PMC3083193 DOI: 10.1074/jbc.m110.215962] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 02/16/2011] [Indexed: 11/06/2022] Open
Abstract
Reflecting the diverse chemistry of plant cell walls, microorganisms that degrade these composite structures synthesize an array of glycoside hydrolases. These enzymes are organized into sequence-, mechanism-, and structure-based families. Genomic data have shown that several organisms that degrade the plant cell wall contain a large number of genes encoding family 43 (GH43) glycoside hydrolases. Here we report the biochemical properties of the GH43 enzymes of a saprophytic soil bacterium, Cellvibrio japonicus, and a human colonic symbiont, Bacteroides thetaiotaomicron. The data show that C. japonicus uses predominantly exo-acting enzymes to degrade arabinan into arabinose, whereas B. thetaiotaomicron deploys a combination of endo- and side chain-cleaving glycoside hydrolases. Both organisms, however, utilize an arabinan-specific α-1,2-arabinofuranosidase in the degradative process, an activity that has not previously been reported. The enzyme can cleave α-1,2-arabinofuranose decorations in single or double substitutions, the latter being recalcitrant to the action of other arabinofuranosidases. The crystal structure of the C. japonicus arabinan-specific α-1,2-arabinofuranosidase, CjAbf43A, displays a five-bladed β-propeller fold. The specificity of the enzyme for arabinan is conferred by a surface cleft that is complementary to the helical backbone of the polysaccharide. The specificity of CjAbf43A for α-1,2-l-arabinofuranose side chains is conferred by a polar residue that orientates the arabinan backbone such that O2 arabinose decorations are directed into the active site pocket. A shelflike structure adjacent to the active site pocket accommodates O3 arabinose side chains, explaining how the enzyme can target O2 linkages that are components of single or double substitutions.
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Affiliation(s)
- Alan Cartmell
- From the Institute for Cell and Molecular Biosciences, Newcastle University, The Medical School, Newcastle upon Tyne NE2 4HH, United Kingdom
- the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Lauren S. McKee
- From the Institute for Cell and Molecular Biosciences, Newcastle University, The Medical School, Newcastle upon Tyne NE2 4HH, United Kingdom
- the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Maria J. Peña
- the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Johan Larsbrink
- the School of Biotechnology, Royal Institute of Technology, AlbaNova University Centre, 10691 Stockholm, Sweden
| | - Harry Brumer
- the School of Biotechnology, Royal Institute of Technology, AlbaNova University Centre, 10691 Stockholm, Sweden
| | - Satoshi Kaneko
- the Food Biotechnology Division, National Food Research Institute, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan, and
| | - Hitomi Ichinose
- the Food Biotechnology Division, National Food Research Institute, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan, and
| | - Richard J. Lewis
- From the Institute for Cell and Molecular Biosciences, Newcastle University, The Medical School, Newcastle upon Tyne NE2 4HH, United Kingdom
| | | | - Harry J. Gilbert
- From the Institute for Cell and Molecular Biosciences, Newcastle University, The Medical School, Newcastle upon Tyne NE2 4HH, United Kingdom
- the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Jon Marles-Wright
- From the Institute for Cell and Molecular Biosciences, Newcastle University, The Medical School, Newcastle upon Tyne NE2 4HH, United Kingdom
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902
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Richter S, Müssig J, Gierlinger N. Functional plant cell wall design revealed by the Raman imaging approach. PLANTA 2011; 233:763-72. [PMID: 21197544 DOI: 10.1007/s00425-010-1338-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Accepted: 12/09/2010] [Indexed: 05/23/2023]
Abstract
Using the Raman imaging approach, the optimization of the plant cell wall design was investigated on the micron level within different tissue types at different positions of a Phormium tenax leaf. Pectin and lignin distribution were visualized and the cellulose microfibril angle (MFA) of the cell walls was determined. A detailed analysis of the Raman spectra extracted from the selected regions, allowed a semi-quantitative comparison of the chemical composition of the investigated tissue types on the micron level. The cell corners of the parenchyma revealed almost pure pectin and the cell wall an amount of 38-49% thereof. Slight lignification was observed in the parenchyma and collenchyma in the top of the leaf and a high variability (7-44%) in the sclerenchyma. In the cell corners and in the cell wall of the sclerenchymatic fibres surrounding the vascular tissue, the highest lignification was observed, which can act as a barrier and protection of the vascular tissue. In the sclerenchyma high variable MFA (4°-40°) was detected, which was related with lignin variability. In the primary cell walls a constant high MFA (57°-58°) was found together with pectin. The different plant cell wall designs on the tissue and microlevel involve changes in chemical composition as well as cellulose microfibril alignment and are discussed and related according to the development and function.
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Affiliation(s)
- Stephan Richter
- Faculty 5/Biomimetics, Biological Materials, University of Applied Sciences Bremen, 28199, Bremen, Germany
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903
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Nosáľová G, Prisenžňáková Ľ, Košťálová Z, Ebringerová A, Hromádková Z. Suppressive effect of pectic polysaccharides from Cucurbita pepo L. var. Styriaca on citric acid-induced cough reflex in guinea pigs. Fitoterapia 2011; 82:357-64. [DOI: 10.1016/j.fitote.2010.11.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Revised: 10/22/2010] [Accepted: 11/02/2010] [Indexed: 12/16/2022]
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904
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Optimization of nitric acid-mediated extraction of pectin from cacao pod husks (Theobroma cacao L.) using response surface methodology. Carbohydr Polym 2011. [DOI: 10.1016/j.carbpol.2011.01.009] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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905
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Abstract
Plant cell walls are complex structures composed of high-molecular-weight polysaccharides, proteins, and lignins. Among the wall polysaccharides, cellulose, a hydrogen-bonded β-1,4-linked glucan microfibril, is the main load-bearing wall component and a key precursor for industrial applications. Cellulose is synthesized by large multi-meric cellulose synthase (CesA) complexes, tracking along cortical microtubules at the plasma membrane. The only known components of these complexes are the cellulose synthase proteins. Recent studies have identified tentative interaction partners for the CesAs and shown that the migratory patterns of the CesA complexes depend on phosphorylation status. These advances may become good platforms for expanding our knowledge about cellulose synthesis in the near future. In addition, our current understanding of cellulose chain polymerization in the context of the CesA complex is discussed.
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Affiliation(s)
- Anne Endler
- Max-Planck-Institute for Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam, Germany
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906
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Lee KJD, Marcus SE, Knox JP. Cell wall biology: perspectives from cell wall imaging. MOLECULAR PLANT 2011; 4:212-9. [PMID: 21199879 DOI: 10.1093/mp/ssq075] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Polysaccharide-rich plant cell walls are important biomaterials that underpin plant growth, are major repositories for photosynthetically accumulated carbon, and, in addition, impact greatly on the human use of plants. Land plant cell walls contain in the region of a dozen major polysaccharide structures that are mostly encompassed by cellulose, hemicelluloses, and pectic polysaccharides. During the evolution of land plants, polysaccharide diversification appears to have largely involved structural elaboration and diversification within these polysaccharide groups. Cell wall chemistry is well advanced and a current phase of cell wall science is aimed at placing the complex polysaccharide chemistry in cellular contexts and developing a detailed understanding of cell wall biology. Imaging cell wall glycomes is a challenging area but recent developments in the establishment of cell wall molecular probe panels and their use in high throughput procedures are leading to rapid advances in the molecular understanding of the spatial heterogeneity of individual cell walls and also cell wall differences at taxonomic levels. The challenge now is to integrate this knowledge of cell wall heterogeneity with an understanding of the molecular and physiological mechanisms that underpin cell wall properties and functions.
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Affiliation(s)
- Kieran J D Lee
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS29JT, UK
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907
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Bandmann V, Kreft M, Homann U. Modes of exocytotic and endocytotic events in tobacco BY-2 protoplasts. MOLECULAR PLANT 2011; 4:241-51. [PMID: 21135068 DOI: 10.1093/mp/ssq072] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
To analyze the kinetics and size of single exo- and endocytotic events in BY-2 protoplasts, we employed cell-attached membrane capacitance measurements. These measurements revealed different modes of fusion and fission of single vesicles. In about half of the observed exocytotic events, fusion occurred transiently, which facilitates rapid recycling of vesicles. In addition, transient sequential or multi-vesicular exocytosis observed in some recordings can contribute to an increase in efficiency of secretory product release. Microscopic analysis of the timescale of cellulose and pectin deposition in protoplasts demonstrates that rebuilding of the cell wall starts soon after isolation of protoplasts and that transient fusion events can fully account for secretion of the required soluble material. The capacitance measurements also allowed us to investigate formation of the fusion pore. We speculate that regulation of secretion may involve control of the length and/or size of fusion pore opening. Together, the different kinetic modes of exo- and endocytosis revealed by capacitance measurements underline the complexity of this process in plants and provide a basis for future research into the underlying mechanisms. The fact that similar fusion/fission kinetics are present in plant and animal cells suggests that many of these mechanisms are highly conserved among eukaryotes.
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Affiliation(s)
- Vera Bandmann
- Institut für Botanik, Technische Universität Darmstadt, 64287 Darmstadt, Germany
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908
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Hassan S, Hugouvieux-Cotte-Pattat N. Identification of two feruloyl esterases in Dickeya dadantii 3937 and induction of the major feruloyl esterase and of pectate lyases by ferulic acid. J Bacteriol 2011; 193:963-70. [PMID: 21169494 PMCID: PMC3028667 DOI: 10.1128/jb.01239-10] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Accepted: 12/03/2010] [Indexed: 11/20/2022] Open
Abstract
The plant-pathogenic bacterium Dickeya dadantii (formerly Erwinia chrysanthemi) produces a large array of plant cell wall-degrading enzymes. Using an in situ detection test, we showed that it produces two feruloyl esterases, FaeD and FaeT. These enzymes cleave the ester link between ferulate and the pectic or xylan chains. FaeD and FaeT belong to the carbohydrate esterase family CE10, and they are the first two feruloyl esterases to be identified in this family. Cleavage of synthetic substrates revealed strong activation of FaeD and FaeT by ferulic acid. The gene faeT appeared to be weakly expressed, and its product, FaeT, is a cytoplasmic protein. In contrast, the gene faeD is strongly induced in the presence of ferulic acid, and FaeD is an extracellular protein secreted by the Out system, responsible for pectinase secretion. The product of the adjacent gene faeR is involved in the positive control of faeD in response to ferulic acid. Moreover, ferulic acid acts in synergy with polygalacturonate to induce pectate lyases, the main virulence determinant of soft rot disease. Feruloyl esterases dissociate internal cross-links in the polysaccharide network of the plant cell wall, suppress the polysaccharide esterifications, and liberate ferulic acid, which contributes to the induction of pectate lyases. Together, these effects of feruloyl esterases could facilitate soft rot disease caused by pectinolytic bacteria.
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Affiliation(s)
- Susan Hassan
- Université de Lyon, Université Lyon 1; INSA-Lyon; and Microbiologie Adaptation et Pathogénie, CNRS UMR5240, Domaine Scientifique de la Doua, Villeurbanne F-69622, France
| | - Nicole Hugouvieux-Cotte-Pattat
- Université de Lyon, Université Lyon 1; INSA-Lyon; and Microbiologie Adaptation et Pathogénie, CNRS UMR5240, Domaine Scientifique de la Doua, Villeurbanne F-69622, France
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909
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Abstract
Carbohydrate-active enzymes face huge substrate diversity in a highly selective manner using only a limited number of available folds. They are therefore subjected to multiple divergent and convergent evolutionary events. This and their frequent modularity render their functional annotation in genomes difficult in a number of cases. In the present paper, a classification of polysaccharide lyases (the enzymes that cleave polysaccharides using an elimination instead of a hydrolytic mechanism) is shown thoroughly for the first time. Based on the analysis of a large panel of experimentally characterized polysaccharide lyases, we examined the correlation of various enzyme properties with the three levels of the classification: fold, family and subfamily. The resulting hierarchical classification, which should help annotate relevant genes in genomic efforts, is available and constantly updated at the Carbohydrate-Active Enzymes Database (http://www.cazy.org).
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910
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Louvet R, Rayon C, Domon JM, Rusterucci C, Fournet F, Leaustic A, Crépeau MJ, Ralet MC, Rihouey C, Bardor M, Lerouge P, Gillet F, Pelloux J. Major changes in the cell wall during silique development in Arabidopsis thaliana. PHYTOCHEMISTRY 2011; 72:59-67. [PMID: 21051061 DOI: 10.1016/j.phytochem.2010.10.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Revised: 10/12/2010] [Accepted: 10/13/2010] [Indexed: 05/08/2023]
Abstract
Fruit development is a highly complex process, which involves major changes in plant metabolism leading to cell growth and differentiation. Changes in cell wall composition and structure play a major role in modulating cell growth. We investigated the changes in cell wall composition and the activities of associated enzymes during the dry fruit development of the model plant Arabidopsis thaliana. Silique development is characterized by several specific phases leading to fruit dehiscence and seed dispersal. We showed that early phases of silique growth were characterized by specific changes in non-cellulosic sugar content (rhamnose, arabinose, xylose, galactose and galacturonic acid). Xyloglucan oligosaccharide mass profiling further showed a strong increase in O-acetylated xyloglucans over the course of silique development, which could suggest a decreased capacity of xyloglucans to be associated with each other or to cellulose. The degree of methylesterification, mediated by the activity of pectin methylesterases (PMEs), decreased over the course of silique growth and dehiscence. The major changes in cell wall composition revealed by our analysis suggest that it could be major determinants in modulating cell wall rheology leading to growth or growth arrest.
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Affiliation(s)
- Romain Louvet
- EA3900-BioPI Biologie des Plantes et contrôle des Insectes ravageurs, Université de Picardie, Amiens, France
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911
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912
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913
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Chlubnová I, Sylla B, Nugier-Chauvin C, Daniellou R, Legentil L, Kralová B, Ferrières V. Natural glycans and glycoconjugates as immunomodulating agents. Nat Prod Rep 2011; 28:937-52. [DOI: 10.1039/c1np00005e] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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914
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Bar-Peled M, O'Neill MA. Plant nucleotide sugar formation, interconversion, and salvage by sugar recycling. ANNUAL REVIEW OF PLANT BIOLOGY 2011; 62:127-55. [PMID: 21370975 DOI: 10.1146/annurev-arplant-042110-103918] [Citation(s) in RCA: 171] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Nucleotide sugars are the universal sugar donors for the formation of polysaccharides, glycoproteins, proteoglycans, glycolipids, and glycosylated secondary metabolites. At least 100 genes encode proteins involved in the formation of nucleotide sugars. These nucleotide sugars are formed using the carbohydrate derived from photosynthesis, the sugar generated by hydrolyzing translocated sucrose, the sugars released from storage carbohydrates, the salvage of sugars from glycoproteins and glycolipids, the recycling of sugars released during primary and secondary cell wall restructuring, and the sugar generated during plant-microbe interactions. Here we emphasize the importance of the salvage of sugars released from glycans for the formation of nucleotide sugars. We also outline how recent studies combining biochemical, genetic, molecular and cellular approaches have led to an increased appreciation of the role nucleotide sugars in all aspects of plant growth and development. Nevertheless, our understanding of these pathways at the single cell level is far from complete.
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Affiliation(s)
- Maor Bar-Peled
- Department of Plant Biology, University of Georgia, Athens, Georgia 30602, USA
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915
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Pectin methylesterase and its proteinaceous inhibitor: a review. Carbohydr Res 2010; 345:2583-95. [DOI: 10.1016/j.carres.2010.10.002] [Citation(s) in RCA: 203] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Revised: 09/30/2010] [Accepted: 10/03/2010] [Indexed: 11/23/2022]
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916
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Oikawa A, Joshi HJ, Rennie EA, Ebert B, Manisseri C, Heazlewood JL, Scheller HV. An integrative approach to the identification of Arabidopsis and rice genes involved in xylan and secondary wall development. PLoS One 2010; 5:e15481. [PMID: 21124849 PMCID: PMC2990762 DOI: 10.1371/journal.pone.0015481] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Accepted: 09/24/2010] [Indexed: 11/19/2022] Open
Abstract
Xylans constitute the major non-cellulosic component of plant biomass. Xylan biosynthesis is particularly pronounced in cells with secondary walls, implying that the synthesis network consists of a set of highly expressed genes in such cells. To improve the understanding of xylan biosynthesis, we performed a comparative analysis of co-expression networks between Arabidopsis and rice as reference species with different wall types. Many co-expressed genes were represented by orthologs in both species, which implies common biological features, while some gene families were only found in one of the species, and therefore likely to be related to differences in their cell walls. To predict the subcellular location of the identified proteins, we developed a new method, PFANTOM (plant protein family information-based predictor for endomembrane), which was shown to perform better for proteins in the endomembrane system than other available prediction methods. Based on the combined approach of co-expression and predicted cellular localization, we propose a model for Arabidopsis and rice xylan synthesis in the Golgi apparatus and signaling from plasma membrane to nucleus for secondary cell wall differentiation. As an experimental validation of the model, we show that an Arabidopsis mutant in the PGSIP1 gene encoding one of the Golgi localized candidate proteins has a highly decreased content of glucuronic acid in secondary cell walls and substantially reduced xylan glucuronosyltransferase activity.
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Affiliation(s)
- Ai Oikawa
- Feedstocks Division, Joint BioEnergy Institute, Emeryville, California, USA
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917
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Localisation pattern of homogalacturonan and arabinogalactan proteins in developing ovules of the gymnosperm plant Larix decidua Mill. ACTA ACUST UNITED AC 2010; 24:75-87. [PMID: 21069390 DOI: 10.1007/s00497-010-0154-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2010] [Accepted: 10/17/2010] [Indexed: 10/18/2022]
Abstract
We have identified and characterised the temporal and spatial distribution of the homogalacturonan (HG) and arabinogalactan proteins (AGP) epitopes that are recognised by the antibodies JIM5, JIM7, LM2, JIM4, JIM8 and JIM13 during ovule differentiation in Larix decidua Mill. The results obtained clearly show differences in the pattern of localisation of specific HG epitopes between generative and somatic cells of the ovule. Immunocytochemical studies revealed that the presence of low-esterified HG is characteristic only of the wall of megasporocyte and megaspores. In maturing female gametophytes, highly esterified HG was the main form present, and the central vacuole of free nuclear gametophytes was particularly rich in this category of HG. This pool will probably be used in cell wall building during cellularisation. The selective labelling obtained with AGP antibodies indicates that some AGPs can be used as markers for gametophytic and sporophytic cells differentiation. Our results demonstrated that the AGPs recognised by JIM4 may constitute molecules determining changes in ovule cell development programs. Just after the end of meiosis, the signal detected with JIM4 labelling appeared only in functional and degenerating megaspores. This suggests that the antigens bound by JIM4 are involved in the initiation of female gametogenesis in L. decidua. Moreover, the analysis of AGPs distribution showed that differentiation of the nucellus cells occurs in the very young ovule stage before megasporogenesis. Throughout the period of ovule development, the pattern of localisation of the studied AGPs was different both in tapetum cells surrounding the gametophyte and in nucellus cells. Changes in the distribution of AGPs were also observed in the nucellus of the mature ovule, and they could represent an indicator of tissue arrangement to interact with the growing pollen tube. The possible role of AGPs in fertilisation is also discussed.
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918
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Ye MB, Lim BO. Dietary pectin regulates the levels of inflammatory cytokines and immunoglobulins in interleukin-10 knockout mice. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:11281-11286. [PMID: 20945935 DOI: 10.1021/jf103262s] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Pectin has protective, anti-inflammatory effects on inflammatory bowel disease (IBD), but the exact mechanism is unknown. Therefore, we investigated the immunological effect of dietary pectin in IL-10(-/-) mice, a murine model for IBD. Cytokine expression, CD4(+) and CD8(+) T cell populations, and immunoglobulin secretion were observed in three groups of mice: normal (BALb/c), IL-10(-/-), and IL-10(-/-) treated with pectin. Pectin treatment reduced expression of TNF-α and GATA-3, an important transcription factor for the Th2 immune response. These mice also expressed lower levels of IgE in the spleen and Peyer's patches (PP) and lower IgG and IgM expression in PP. Interestingly, IL-10 deficiency resulted in lower CD4(+) and CD8(+) populations in the spleen, mesenteric lymph node (MLN), and PP; however, pectin counteracted these declines in the MLN and PP. Therefore, dietary pectin downregulates the inflammatory response in the colon by moderating the production of proinflammatory cytokines and immunoglobulins.
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Affiliation(s)
- Michael B Ye
- Department of Applied Biochemistry, College of Biomedical and Health Science, Konkuk University, 322 Danwol, Chungju-si, Chungbuk-do, 380-701, Korea
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919
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Jiang MH, Zhu L, Jiang JG. Immunoregulatory actions of polysaccharides from Chinese herbal medicine. Expert Opin Ther Targets 2010; 14:1367-402. [DOI: 10.1517/14728222.2010.531010] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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920
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Yoneda A, Ito T, Higaki T, Kutsuna N, Saito T, Ishimizu T, Osada H, Hasezawa S, Matsui M, Demura T. Cobtorin target analysis reveals that pectin functions in the deposition of cellulose microfibrils in parallel with cortical microtubules. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 64:657-67. [PMID: 21070417 DOI: 10.1111/j.1365-313x.2010.04356.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Cellulose and pectin are major components of primary cell walls in plants, and it is believed that their mechanical properties are important for cell morphogenesis. It has been hypothesized that cortical microtubules guide the movement of cellulose microfibril synthase in a direction parallel with the microtubules, but the mechanism by which this alignment occurs remains unclear. We have previously identified cobtorin as an inhibitor that perturbs the parallel relationship between cortical microtubules and nascent cellulose microfibrils. In this study, we searched for the protein target of cobtorin, and we found that overexpression of pectin methylesterase and polygalacturonase suppressed the cobtorin-induced cell-swelling phenotype. Furthermore, treatment with polygalacturonase restored the deposition of cellulose microfibrils in the direction parallel with cortical microtubules, and cobtorin perturbed the distribution of methylated pectin. These results suggest that control over the properties of pectin is important for the deposition of cellulose microfibrils and/or the maintenance of their orientation parallel with the cortical microtubules.
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Affiliation(s)
- Arata Yoneda
- Biomass Engineering Program, RIKEN, 1-7-22, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.
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921
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Tyler L, Bragg JN, Wu J, Yang X, Tuskan GA, Vogel JP. Annotation and comparative analysis of the glycoside hydrolase genes in Brachypodium distachyon. BMC Genomics 2010; 11:600. [PMID: 20973991 PMCID: PMC3091745 DOI: 10.1186/1471-2164-11-600] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Accepted: 10/25/2010] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Glycoside hydrolases cleave the bond between a carbohydrate and another carbohydrate, a protein, lipid or other moiety. Genes encoding glycoside hydrolases are found in a wide range of organisms, from archea to animals, and are relatively abundant in plant genomes. In plants, these enzymes are involved in diverse processes, including starch metabolism, defense, and cell-wall remodeling. Glycoside hydrolase genes have been previously cataloged for Oryza sativa (rice), the model dicotyledonous plant Arabidopsis thaliana, and the fast-growing tree Populus trichocarpa (poplar). To improve our understanding of glycoside hydrolases in plants generally and in grasses specifically, we annotated the glycoside hydrolase genes in the grasses Brachypodium distachyon (an emerging monocotyledonous model) and Sorghum bicolor (sorghum). We then compared the glycoside hydrolases across species, at the levels of the whole genome and individual glycoside hydrolase families. RESULTS We identified 356 glycoside hydrolase genes in Brachypodium and 404 in sorghum. The corresponding proteins fell into the same 34 families that are represented in rice, Arabidopsis, and poplar, helping to define a glycoside hydrolase family profile which may be common to flowering plants. For several glycoside hydrolase familes (GH5, GH13, GH18, GH19, GH28, and GH51), we present a detailed literature review together with an examination of the family structures. This analysis of individual families revealed both similarities and distinctions between monocots and eudicots, as well as between species. Shared evolutionary histories appear to be modified by lineage-specific expansions or deletions. Within GH families, the Brachypodium and sorghum proteins generally cluster with those from other monocots. CONCLUSIONS This work provides the foundation for further comparative and functional analyses of plant glycoside hydrolases. Defining the Brachypodium glycoside hydrolases sets the stage for Brachypodium to be a grass model for investigations of these enzymes and their diverse roles in planta. Insights gained from Brachypodium will inform translational research studies, with applications for the improvement of cereal crops and bioenergy grasses.
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Affiliation(s)
- Ludmila Tyler
- USDA-ARS Western Regional Research Center, Albany, CA 94710, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
| | - Jennifer N Bragg
- USDA-ARS Western Regional Research Center, Albany, CA 94710, USA
| | - Jiajie Wu
- USDA-ARS Western Regional Research Center, Albany, CA 94710, USA
- Department of Plant Sciences, University of California, Davis, CA 95616, USA
| | - Xiaohan Yang
- Biosciences Division and BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Gerald A Tuskan
- Biosciences Division and BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - John P Vogel
- USDA-ARS Western Regional Research Center, Albany, CA 94710, USA
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922
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Phylogenetic, microbiological, and glycoside hydrolase diversities within the extremely thermophilic, plant biomass-degrading genus Caldicellulosiruptor. Appl Environ Microbiol 2010; 76:8084-92. [PMID: 20971878 DOI: 10.1128/aem.01400-10] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Phylogenetic, microbiological, and comparative genomic analyses were used to examine the diversity among members of the genus Caldicellulosiruptor, with an eye toward the capacity of these extremely thermophilic bacteria to degrade the complex carbohydrate content of plant biomass. Seven species from this genus (C. saccharolyticus, C. bescii, C. hydrothermalis, C. owensensis, C. kronotskyensis, C. lactoaceticus, and C. kristjanssonii) were compared on the basis of 16S rRNA gene phylogeny and cross-species DNA-DNA hybridization to a whole-genome C. saccharolyticus oligonucleotide microarray, revealing that C. saccharolyticus was the most divergent within this group. Growth physiology of the seven Caldicellulosiruptor species on a range of carbohydrates showed that, while all could be cultivated on acid-pretreated switchgrass, only C. saccharolyticus, C. bescii, C. kronotskyensis, and C. lactoaceticus were capable of hydrolyzing Whatman no. 1 filter paper. Two-dimensional gel electrophoresis of the secretomes from cells grown on microcrystalline cellulose revealed that the cellulolytic species also had diverse secretome fingerprints. The C. saccharolyticus secretome contained a prominent S-layer protein that appears in the cellulolytic Caldicellulosiruptor species, suggesting a possible role in cell-substrate interactions. Growth physiology also correlated with glycoside hydrolase (GH) and carbohydrate-binding module (CBM) inventories for the seven bacteria, as deduced from draft genome sequence information. These inventories indicated that the absence of a single GH and CBM family was responsible for diminished cellulolytic capacity. Overall, the genus Caldicellulosiruptor appears to contain more genomic and physiological diversity than previously reported, and this argues for continued efforts to isolate new members from high-temperature terrestrial biotopes.
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923
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Kalluri UC, Keller M. Bioenergy research: a new paradigm in multidisciplinary research. J R Soc Interface 2010; 7:1391-401. [PMID: 20542958 PMCID: PMC3227023 DOI: 10.1098/rsif.2009.0564] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Accepted: 05/10/2010] [Indexed: 12/28/2022] Open
Abstract
The field of biology is becoming increasingly interdisciplinary and cross-cutting. This changing research atmosphere is creating the way for a new kind of enquiry that while building upon the traditional research establishment is providing a new multidisciplinary framework to more effectively address scientific grand challenges. Using the US Department of Energy sponsored BioEnergy Science Center as an example, we highlight how impactful breakthroughs in biofuel science can be achieved within a large cross-disciplinary team environment. Such transformational insights are key to furthering our understanding and in generating models, theories and processes that can be used to overcome recalcitrance of biomass for sustainable biofuel production. Multidisciplinary approaches have an increasingly greater role to play in meeting rising demands for food, fibre, energy, clean environment and good health. Discoveries achieved by diverse minds and cross-applications of tools and analytical approaches have tremendous potential to fill existing knowledge gaps, clear roadblocks and facilitate translation of basic sciences discoveries as solutions towards addressing some of the most pressing global issues.
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Affiliation(s)
- Udaya C. Kalluri
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
- BESC BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Martin Keller
- Biological and Environmental Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN, USA
- BESC BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, USA
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924
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Abbott DW, Gilbert HJ, Boraston AB. The active site of oligogalacturonate lyase provides unique insights into cytoplasmic oligogalacturonate beta-elimination. J Biol Chem 2010; 285:39029-38. [PMID: 20851883 DOI: 10.1074/jbc.m110.153981] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Oligogalacturonate lyases (OGLs; now also classified as pectate lyase family 22) are cytoplasmic enzymes found in pectinolytic members of Enterobacteriaceae, such as the enteropathogen Yersinia enterocolitica. OGLs utilize a β-elimination mechanism to preferentially catalyze the conversion of saturated and unsaturated digalacturonate into monogalacturonate and the 4,5-unsaturated monogalacturonate-like molecule, 5-keto-4-deoxyuronate. To provide mechanistic insights into the specificity of this enzyme activity, we have characterized the OGL from Y. enterocolitica, YeOGL, on oligogalacturonides and determined its three-dimensional x-ray structure to 1.65 Å. The model contains a Mn(2+) atom in the active site, which is coordinated by three histidines, one glutamine, and an acetate ion. The acetate mimics the binding of the uronate group of galactourono-configured substrates. These findings, in combination with enzyme kinetics and metal supplementation assays, provide a framework for modeling the active site architecture of OGL. This enzyme appears to contain a histidine for the abstraction of the α-proton in the -1 subsite, a residue that is highly conserved throughout the OGL family and represents a unique catalytic base among pectic active lyases. In addition, we present a hypothesis for an emerging relationship observed between the cellular distribution of pectate lyase folding and the distinct metal coordination chemistries of pectate lyases.
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Affiliation(s)
- D Wade Abbott
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602, USA.
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925
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926
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Xu Y, Dong Q, Qiu H, Cong R, Ding K. Structural Characterization of an Arabinogalactan from Platycodon grandiflorum Roots and Antiangiogenic Activity of Its Sulfated Derivative. Biomacromolecules 2010; 11:2558-66. [DOI: 10.1021/bm100402n] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Yuxia Xu
- Glycobiology and Glycochemistry Laboratory, Joint Laboratory for The Research of Chinese Herbal Polysaccharides, Shanghai Institute of Materia Medica, Chinese Academy of Sciences and Infinitus, Shanghai 201203, China
| | - Qun Dong
- Glycobiology and Glycochemistry Laboratory, Joint Laboratory for The Research of Chinese Herbal Polysaccharides, Shanghai Institute of Materia Medica, Chinese Academy of Sciences and Infinitus, Shanghai 201203, China
| | - Hong Qiu
- Glycobiology and Glycochemistry Laboratory, Joint Laboratory for The Research of Chinese Herbal Polysaccharides, Shanghai Institute of Materia Medica, Chinese Academy of Sciences and Infinitus, Shanghai 201203, China
| | - Renhuai Cong
- Glycobiology and Glycochemistry Laboratory, Joint Laboratory for The Research of Chinese Herbal Polysaccharides, Shanghai Institute of Materia Medica, Chinese Academy of Sciences and Infinitus, Shanghai 201203, China
| | - Kan Ding
- Glycobiology and Glycochemistry Laboratory, Joint Laboratory for The Research of Chinese Herbal Polysaccharides, Shanghai Institute of Materia Medica, Chinese Academy of Sciences and Infinitus, Shanghai 201203, China
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927
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Dardelle F, Lehner A, Ramdani Y, Bardor M, Lerouge P, Driouich A, Mollet JC. Biochemical and immunocytological characterizations of Arabidopsis pollen tube cell wall. PLANT PHYSIOLOGY 2010; 153:1563-76. [PMID: 20547702 PMCID: PMC2923879 DOI: 10.1104/pp.110.158881] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
During plant sexual reproduction, pollen germination and tube growth require development under tight spatial and temporal control for the proper delivery of the sperm cells to the ovules. Pollen tubes are fast growing tip-polarized cells able to perceive multiple guiding signals emitted by the female organ. Adhesion of pollen tubes via cell wall molecules may be part of the battery of signals. In order to study these processes, we investigated the cell wall characteristics of in vitro-grown Arabidopsis (Arabidopsis thaliana) pollen tubes using a combination of immunocytochemical and biochemical techniques. Results showed a well-defined localization of cell wall epitopes. Low esterified homogalacturonan epitopes were found mostly in the pollen tube wall back from the tip. Xyloglucan and arabinan from rhamnogalacturonan I epitopes were detected along the entire tube within the two wall layers and the outer wall layer, respectively. In contrast, highly esterified homogalacturonan and arabinogalactan protein epitopes were found associated predominantly with the tip region. Chemical analysis of the pollen tube cell wall revealed an important content of arabinosyl residues (43%) originating mostly from (1-->5)-alpha-L-arabinan, the side chains of rhamnogalacturonan I. Finally, matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis of endo-glucanase-sensitive xyloglucan showed mass spectra with two dominant oligosaccharides (XLXG/XXLG and XXFG), both being mono O-acetylated, and accounting for over 68% of the total ion signals. These findings demonstrate that the Arabidopsis pollen tube wall has its own characteristics compared with other cell types in the Arabidopsis sporophyte. These structural features are discussed in terms of pollen tube cell wall biosynthesis and growth dynamics.
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928
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Fuentes S, Pires N, Østergaard L. A clade in the QUASIMODO2 family evolved with vascular plants and supports a role for cell wall composition in adaptation to environmental changes. PLANT MOLECULAR BIOLOGY 2010; 73:605-615. [PMID: 20464626 DOI: 10.1007/s11103-010-9640-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2009] [Accepted: 04/21/2010] [Indexed: 05/28/2023]
Abstract
The evolution of plant vascular tissue is tightly linked to the evolution of specialised cell walls. Mutations in the QUASIMODO2 (QUA2) gene from Arabidopsis thaliana were previously shown to result in cell adhesion defects due to reduced levels of the cell wall component homogalacturonic acid. In this study, we provide additional information about the role of QUA2 and its closest paralogues, QUASIMODO2 LIKE1 (QUL1) and QUL2. Within the extensive QUA2 family, our phylogenetic analysis shows that these three genes form a clade that evolved with vascular plants. Consistent with a possible role of this clade in vasculature development, QUA2 is highly expressed in the vascular tissue of embryos and inflorescence stems and overexpression of QUA2 resulted in temperature-sensitive xylem collapse. Moreover, in-depth characterisation of qua2 qul1 qul2 triple mutant and 35S::QUA2 overexpression plants revealed contrasting temperature-dependent stem development with dramatic effects on stem width. Taken together, our results suggest that the QUA2-specific clade contributed to the evolution of vasculature and illustrate the important role that modification of cell wall composition plays in the adaptation to changing environmental conditions, including changes in temperature.
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Affiliation(s)
- Sara Fuentes
- Department of Crop Genetics, John Innes Centre, Colney Lane, Norwich NR4 7UH, UK
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929
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Yin Y, Chen H, Hahn MG, Mohnen D, Xu Y. Evolution and function of the plant cell wall synthesis-related glycosyltransferase family 8. PLANT PHYSIOLOGY 2010; 153:1729-46. [PMID: 20522722 PMCID: PMC2923890 DOI: 10.1104/pp.110.154229] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Accepted: 06/01/2010] [Indexed: 05/17/2023]
Abstract
Carbohydrate-active enzyme glycosyltransferase family 8 (GT8) includes the plant galacturonosyltransferase1-related gene family of proven and putative alpha-galacturonosyltransferase (GAUT) and GAUT-like (GATL) genes. We computationally identified and investigated this family in 15 fully sequenced plant and green algal genomes and in the National Center for Biotechnology Information nonredundant protein database to determine the phylogenetic relatedness of the GAUTs and GATLs to other GT8 family members. The GT8 proteins fall into three well-delineated major classes. In addition to GAUTs and GATLs, known or predicted to be involved in plant cell wall biosynthesis, class I also includes a lower plant-specific GAUT and GATL-related (GATR) subfamily, two metazoan subfamilies, and proteins from other eukaryotes and cyanobacteria. Class II includes galactinol synthases and plant glycogenin-like starch initiation proteins that are not known to be directly involved in cell wall synthesis, as well as proteins from fungi, metazoans, viruses, and bacteria. Class III consists almost entirely of bacterial proteins that are lipooligo/polysaccharide alpha-galactosyltransferases and alpha-glucosyltransferases. Sequence motifs conserved across all GT8 subfamilies and those specific to plant cell wall-related GT8 subfamilies were identified and mapped onto a predicted GAUT1 protein structure. The tertiary structure prediction identified sequence motifs likely to represent key amino acids involved in catalysis, substrate binding, protein-protein interactions, and structural elements required for GAUT1 function. The results show that the GAUTs, GATLs, and GATRs have a different evolutionary origin than other plant GT8 genes, were likely acquired from an ancient cyanobacterium (Synechococcus) progenitor, and separate into unique subclades that may indicate functional specialization.
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Affiliation(s)
| | | | | | - Debra Mohnen
- Computational Systems Biology Laboratory and Institute of Bioinformatics (Y.Y., H.C., Y.X.), BioEnergy Science Center (Y.Y., M.G.H., D.M., Y.X.), Department of Plant Biology (M.G.H.), Complex Carbohydrate Research Center (M.G.H., D.M.), and Department of Biochemistry and Molecular Biology (D.M., Y.X.), University of Georgia, Athens, Georgia 30602
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930
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Sun L, van Nocker S. Analysis of promoter activity of members of the PECTATE LYASE-LIKE (PLL) gene family in cell separation in Arabidopsis. BMC PLANT BIOLOGY 2010; 10:152. [PMID: 20649977 PMCID: PMC3017822 DOI: 10.1186/1471-2229-10-152] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Accepted: 07/22/2010] [Indexed: 05/18/2023]
Abstract
BACKGROUND Pectate lyases depolymerize pectins by catalyzing the eliminative cleavage of alpha-1,4-linked galacturonic acid. Pectate lyase-like (PLL) genes make up among the largest and most complex families in plants, but their cellular and organismal roles have not been well characterized, and the activity of these genes has been assessed only at the level of entire organs or plant parts, potentially obscuring important sub-organ or cell-type-specific activities. As a first step to understand the potential functional diversity of PLL genes in plants and specificity of individual genes, we utilized a reporter gene approach to document the spatial and temporal promoter activity for 23 of the 26 members of the Arabidopsis thaliana (Arabidopsis) PLL gene family throughout development, focusing on processes involving cell separation. RESULTS Numerous PLL promoters directed activity in localized domains programmed for cell separation, such as the abscission zones of the sepal, petal, stamen, and seed, as well as the fruit dehiscence zone. Several drove activity in cell types expected to facilitate separation, including the style and root endodermal and cortical layers during lateral root emergence. However, PLL promoters were active in domains not obviously programmed for separation, including the stipule, hydathode and root axis. Nearly all PLL promoters showed extensive overlap of activity in most of the regions analyzed. CONCLUSIONS Our results document potential for involvement of PLL genes in numerous aspects of growth and development both dependent and independent of cell separation. Although the complexity of the PLL gene family allows for enormous potential for gene specialization through spatial or temporal regulation, the high degree of overlap of activity among the PLL promoters suggests extensive redundancy. Alternatively, functional specialization might be determined at the post-transcriptional or protein level.
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Affiliation(s)
- Lingxia Sun
- Department of Horticulture, Michigan State University, East Lansing, MI, USA
| | - Steven van Nocker
- Department of Horticulture, Michigan State University, East Lansing, MI, USA
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931
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Chibbar RN, Ambigaipalan P, Hoover R. REVIEW: Molecular Diversity in Pulse Seed Starch and Complex Carbohydrates and Its Role in Human Nutrition and Health. Cereal Chem 2010. [DOI: 10.1094/cchem-87-4-0342] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Ravindra N. Chibbar
- Dept. of Plant Sciences, University of Saskatchewan, Saskatoon, SK, Canada
- Corresponding author. E‐mail:
| | | | - Ratnajothi Hoover
- Department of Biochemistry, Memorial University of Newfoundland, St Johns, Newfoundland, Canada
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932
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Duan J, Dong Q, Ding K, Fang J. Characterization of a pectic polysaccharide from the leaves of Diospyros kaki and its modulating activity on lymphocyte proliferation. Biopolymers 2010; 93:649-56. [PMID: 20235231 DOI: 10.1002/bip.21430] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Pectin is a group of carbohydrate polymers constructing the primary cell walls and the middle lamella of terrestrial plants. Herein, we demonstrated the structure and immunomodulatory activity of the major pectic polysaccharide DL-3B(2) isolated from the leaves of Diospyros kaki. Based on composition analysis, methylation analysis, two-step acid hydrolysis, lithium-mediated selective degradation, (13)C NMR spectroscopy, and electrospray ionization mass spectrometry, DL-3B(2) was found to contain an alpha-1, 4-linked galacturonic acid (GalA) backbone with some insertions of alpha-1, 2-linked rhamnose residues. The arabinan- and arabinogalactan-side chains were attached to O-4 of the rhamnose residues, whereas the linear arabinoxylan was probably linked to O-3 of the GalA residues. Immunological tests in vitro showed that DL-3B(2) could help stimulate lipopolysaccharide-induced B lymphocyte proliferation, but not ConA-induced T lymphocyte proliferation, and that the arabinose residues play a role in maintaining this immunological activity.
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Affiliation(s)
- Jinyou Duan
- Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201203, People's Republic of China.
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933
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Harholt J, Suttangkakul A, Vibe Scheller H. Biosynthesis of pectin. PLANT PHYSIOLOGY 2010; 153:384-95. [PMID: 20427466 PMCID: PMC2879803 DOI: 10.1104/pp.110.156588] [Citation(s) in RCA: 335] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Accepted: 04/27/2010] [Indexed: 05/17/2023]
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934
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Scanlan EM, Mackeen MM, Wormald MR, Davis BG. Synthesis and Solution-Phase Conformation of the RG-I Fragment of the Plant Polysaccharide Pectin Reveals a Modification-Modulated Assembly Mechanism. J Am Chem Soc 2010; 132:7238-9. [DOI: 10.1021/ja9090963] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Eoin M. Scanlan
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K., and Glycobiology Institute, Department of Biochemistry, Oxford University, South Parks Road, Oxford OX1 3QU, U.K
| | - Mukram M. Mackeen
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K., and Glycobiology Institute, Department of Biochemistry, Oxford University, South Parks Road, Oxford OX1 3QU, U.K
| | - Mark R. Wormald
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K., and Glycobiology Institute, Department of Biochemistry, Oxford University, South Parks Road, Oxford OX1 3QU, U.K
| | - Benjamin G. Davis
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K., and Glycobiology Institute, Department of Biochemistry, Oxford University, South Parks Road, Oxford OX1 3QU, U.K
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935
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Codée JDC, Christina AE, Walvoort MTC, Overkleeft HS, van der Marel GA. Uronic acids in oligosaccharide and glycoconjugate synthesis. Top Curr Chem (Cham) 2010; 301:253-89. [PMID: 21222193 DOI: 10.1007/128_2010_111] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This chapter describes the assembly of uronic acid containing oligosaccharides and glycoconjugates. Two strategies are available to access these target molecules, namely a pre-glycosylation oxidation approach, in which uronic acid building blocks are used, and a post-glycosylation oxidation strategy, which employs an oxidation step after the assembly of the oligosaccharide chain. Because uronic acid building blocks are generally considered to be less reactive than their non-oxidized counterparts, the latter approach has found most application in carbohydrate synthesis. With the aid of selected examples of recent syntheses of biologically relevant oligosaccharides and glycoconjugates, the reactivity of different uronic acid building blocks is evaluated. From these examples it is apparent that the generally assumed low reactivity of uronic acids does not a priori rule out an efficient assembly of these target compounds. Besides influencing the reactivity of a given pyranoside, the C-5 carboxylic acid function can also have a profound effect on the stereochemical course of a glycosylation reaction, which can be exploited in the stereoselective formation of glycosidic bonds.
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Affiliation(s)
- Jeroen D C Codée
- Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands.
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