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Results 51 - 100 of 2012
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Hobb Rhonda I - - 2010
Capsule expression in Neisseria meningitidis is encoded by the cps locus comprised of genes required for biosynthesis and surface translocation. Located adjacent to the gene encoding the polysialyltransferase in serogroups expressing sialic acid-containing capsule, NMB0065 is likely a member of the cps locus, but it is not found in serogroups ...
Roy Sumita - - 2010
Tannerella forsythia is a key contributor to periodontitis, but little is known of its virulence mechanisms. In this study we have investigated the role of sialic acid in biofilm growth of this periodontal pathogen. Our data show that biofilm growth of T. forsythia is stimulated by sialic acid, glycolyl sialic ...
Chen Xi - - 2010
Sialic acids are a subset of nonulosonic acids, which are nine-carbon alpha-keto aldonic acids. Natural existing sialic acid-containing structures are presented in different sialic acid forms, various sialyl linkages, and on diverse underlying glycans. They play important roles in biological, pathological, and immunological processes. Sialobiology has been a challenging and ...
Greganova Eva E Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012 Bern, - - 2010
In the tsetse fly, the surface of Trypanosoma congolense parasites is covered by a dense layer of glycosylphosphatidylinositol (GPI)-anchored molecules. These include EPGENGT procyclin and protease resistant surface molecule (PRS), as well as congolense epimastigote-specific protein, CESP, and glutamic acid- and alanine-rich protein (GARP). The GPI structures of EPGENGT and ...
Bondioli Lucia - - 2010
There is a broad interest in the development of nanoparticles (NPs) carrying on their surface carbohydrates such as sialic acids. It is known that these carbohydrates influence the biological and physical properties of biopharmaceutical proteins and living cells. Macromolecular compounds containing these carbohydrates showed an anti-recognition effect, exert an antiviral ...
Kiss Zoltán - - 2010
Cloning of the human erythropoietin (EPO) gene and development of the first recombinant human erythropoietin (rHuEPO) drug were truly breakthroughs. This allowed a deeper understanding of the structure and pharmacology of rHuEpo, which in turn inspired the discovery and development of additional erythropoiesis-stimulating agents (ESAs). In vivo specific activity and ...
Mochel F - - 2010
To investigate body fluids of patients with undiagnosed leukodystrophies using in vitro (1)H-NMR spectroscopy (H-NMRS). We conducted a cross-sectional study using high-resolution in vitro H-NMRS on CSF and urine samples. We found a significant increase of free sialic acid in CSF or urine in 6 of 41 patients presenting with ...
Sakarya Serhan - - 2010
To initiate infection, bacteria must adhere to and colonize host tissues. Specific and nonspecific mechanisms participate in the adherence process. Salmonella enterica ssp. enterica serovar Typhi (S. Typhi) must first adhere to the intestinal epithelium to invade and disseminate throughout the host. In this study, the role of colonic epithelial ...
Sawada Yoshiharu - - 2010
An efficient synthesis of gamma-lactone-type sialic acid, which is an isomer of 2,3-dehydrosialic acid, was achieved from the corresponding sialic ester. The sialic ester was reconstructed from the gamma-lactone in a 95% yield. The gamma-lactone structure was determined by methylating to its corresponding methyl ether.
de Wilde Martijn C - - 2010
The effect of supplementation with the omega 3 polyunsaturated fatty acid (n3 PUFA) docosahexaenoic acid (DHA) on membrane composition and amyloid-β₁₋₄₂ (Aβ₄₂) secretion was studied in human amyloid-β protein precursor-transfected Chinese Hamster Ovary (CHO) cells. Twenty-four hour incubation with a range of DHA concentrations resulted in a dose-dependent increase in ...
Yanagihara Shigehiro - - 2010
Assessment of biological potency and its comparison with clinical effects are important in the quality control of therapeutic glycoproteins. Animal models are usually used for evaluating bioactivity of these compounds. However, alternative methods are required to simplify the bioassay and avoid ethical issues associated with animal studies. Negatively charged sialic ...
Ando Hiromune - - 2010
It is well known that gangliosides, sialic acid-containing glycosphingolipids, play important roles in diverse biological processes associated with cell development, immune response, cancer metastasis, infection, and signal transduction. Synthetic chemistry of ganglioside has been promoting the elucidation of the ganglioside functions at the molecular level by the supply of homogenous ...
Yodoshi Masahiro - - 2010
Serotonin-bonded silica was developed for specific extraction of sialic-acid-containing glycans and glycopeptides. Serotonin, coupled by reductive amination with aldehyde silica particles via its ethylamino group, has strong affinity to sialic acid in glycan chain termini. Sialylated glycans trapped on serotonin silica particles are released by washing with ammonium acetate solution, ...
Liu Xin - - 2010
O-Acetylation is one of the major modifications of sialic acids that significantly alters biological properties of the parent molecule. These O-acetylated forms are components of the cellular membrane and can affect physiological and pathological responses. Understanding the role of N-glycans in physiology is of increasing relevance to cellular biologists in ...
Spadafora Carmenza - - 2010
Plasmodium falciparum is a highly lethal malaria parasite of humans. A major portion of its life cycle is dedicated to invading and multiplying inside erythrocytes. The molecular mechanisms of erythrocyte invasion are incompletely understood. P. falciparum depends heavily on sialic acid present on glycophorins to invade erythrocytes. However, a significant ...
Homann Arne - - 2010
Sialic acids are located at the termini of mammalian cell-surface glycostructures, which participate in essential interaction processes including adhesion of pathogens prior to infection and immunogenicity. Here we present the synthesis and bioorthogonal metabolic incorporation of the sialic acid analogue N-(1-oxohex-5-ynyl)neuraminic acid (Neu5Hex) into the cell-surface glycocalyx of a human ...
López-Morales Dolores - - 2010
Altered sialylation has been observed during oncogenic transformation. Sialylated oligosaccharides of glycoproteins and glycolipids have been implicated in tumor progression and metastases. In the cervical cancer high levels of sialic acid have been reported in the patients serum, and an increased of total sialic acid concentration has been reported for ...
Yu Hai - - 2009
In order to understand the biological importance of naturally occurring sialic acid variations on disialyl structures in nature, we developed an efficient two-step multienzyme approach for the synthesis of a series of GD3 ganglioside oligosaccharides and other disialyl glycans containing a terminal Siaalpha2-8Sia component with different natural and non-natural sialic ...
Severi Emmanuele - - 2010
The function of sialic acids in the biology of bacterial pathogens is reflected by the diverse range of solute transporters that can recognize these sugar acids. Here, we use an Escherichia coliDeltananT strain to characterize the function of known and proposed bacterial sialic acid transporters. We discover that the STM1128 ...
Kim Seonghun - - 2010
Corynebacterium diphtheriae, a pathogenic Gram-positive bacterium, contains sialic acids on its cell surface, but no genes related to sialic acid decoration or metabolism have been reported in C. diphtheriae. In the present study, we have identified a putative sialidase gene, nanH, from C. diphtheriae KCTC3075 and characterized its product for ...
Top?uo?lu Canan - - 2010
OBJECTIVES: To investigate and discuss the total-, lipid-associated, and thrombocyte-sialic acid levels in chronic heart failure (CHF) patients. DESIGN AND METHODS: Thirty-one chronic heart failure patients and 38 healthy controls were included in the study. Serum total sialic acid (TSA), lipid associated sialic acid (LASA), thrombocyte sialic acid (TrSA) were ...
McGrath Rachel T - - 2010
von Willebrand factor (VWF) multimeric composition is regulated in plasma by ADAMTS13. VWF deglycosylation enhances proteolysis by ADAMTS13. In this study, the role of terminal sialic acid residues on VWF glycans in mediating proteolysis by ADAMTS13 was investigated. Quantification and distribution of VWF sialylation was examined by sequential digestion and ...
Al-qattan Mohammed Noor - - 2010
A molecular docking tool of AutoDock3.05 was evaluated for its ability to reproduce experimentally determined affinities of various sialic acid analogues toward hemagglutinin of influenza A virus. With the exception of those with a C6-modified glycerol side chain, the experimental binding affinities of most sialic acid analogues (C2, C4 and ...
Ozt?rk L Ko? - - 2010
OBJECTIVES: This study investigated salivary lipid peroxidation (LPO) as an oxidative stress marker and salivary total sialic acid (TSA) as an inflammatory response during gestation and postpartum. DESIGN AND METHODS: Salivary LPO and TSA levels, using the Ledwozyw and Warren methods respectively, were obtained in healthy pregnant women followed up ...
Cao Hongzhi - - 2009
para-Nitrophenol-tagged sialyl galactosides containing sialic acid derivatives in which the C5 hydroxyl group of sialic acids was systematically substituted with a hydrogen, a fluorine, a methoxyl or an azido group were successfully synthesized using an efficient chemoenzymatic approach. These compounds were used as valuable probes in high-throughput screening assays to ...
Takashima Shou - - 2009
It is commonly accepted that sialic acids do not exist in plants. However, putative gene homologs of animal sialyltransferases and CMP-sialic acid transporters have been detected in the genomes of some plants. To elucidate the physiological functions of these genes, we cloned 2 cDNAs from Oryza sativa (Japanese rice), each ...
Liu Feng - - 2009
The Neisseria meningitidis sialic acid synthase (NeuB) catalyzes the metal-dependent condensation of N-acetylmannosamine (ManNAc) and phosphoenolpyruvate (PEP) to generate N-acetylneuraminic acid (NeuAc or sialic acid). N. meningitidis is a causative agent of meningitis and produces a capsular polysaccharide comprised of polysialic acid. This allows it to evade the immune system ...
Bork Kaya - - 2009
The number of therapeutic proteins has increased dramatically over the past years and most of the therapeutic proteins in the market today are glycoproteins. Usually, recombinant glycoproteins are produced in mammalian cell lines, such as Chinese-hamster-ovary-cells to obtain mammalian-type of glycosylation. The terminal monosaccharide of N-linked complex glycans is typically ...
Iglesias Rosario - - 2010
Sialic acid-binding dwarf elder agglutinin (SEA) present only in rhizomes of the medicinal plant Sambucus ebulus L., was found to be a tetrameric glycoprotein consisting of two covalently-associated dimers of an enzymic A chain with rRNA N-glycosidase activity (EC 3.2.2.22) linked to a B chain with agglutinin properties. The lectin ...
Wirth Christophe - - 2009
Sialic acids are acidic sugars present mostly on vertebrate cell surfaces, which can be metabolized by bacteria and act as an inflammation signal. N-Acetylneuraminic acid, the most abundant sialic acid, can enter into Escherichia coli K12 through NanC, an N-acetylneuraminic acid-inducible outer-membrane channel. With its 215 residues, NanC belongs to ...
Steenbergen Susan M - - 2009
The nanATEK-yhcH, yjhATS, and yjhBC operons in Escherichia coli are coregulated by environmental N-acetylneuraminic acid, the most prevalent sialic acid in nature. Here we show that YjhS (NanS) is a probable 9-O-acetyl N-acetylneuraminic acid esterase required for E. coli to grow on this alternative sialic acid, which is commonly found ...
Carlescu Irina - - 2010
The purpose of this programme was to synthesize and analyze new bioconjugates of interest for the potential inhibition of the influenza virus, using poly(aspartimide) as a polymer support. The macromolecular targets were obtained by attaching various sialic acid-linker-amine compounds to poly(aspartimide). (1)H and (13)C NMR studies were then performed to ...
Cao Hongzhi - - 2009
A convenient chemoenzymatic strategy for synthesizing sialosides containing a C5-diversified sialic acid was developed. The alpha2,3- and alpha2,6-linked sialosides containing a 5-azido neuraminic acid synthesized by a highly efficient one-pot three-enzyme approach were converted to C5''-amino sialosides, which were used as common intermediates for chemical parallel synthesis to quickly generate ...
Sprenger Norbert - - 2009
Old age is linked to numerous changes of body functions such as salivation, gastrointestinal motility, and permeability all linked to central and enteric nervous system decline. Thus, gut motility and barrier functions suffer. Sialic acid plays a key role in the nervous system at large and for many receptor functions ...
Gao Zheng-Xi - - 2009
A straightforward synthesis of 4-amido-N(5)-acetyl-4-deoxyneuraminic acid, a key precursor to various 4-amidoneuraminic acid analogues, has been achieved using a highly regioselective and diastereoselective [3 + 2]-cycloaddition of d-mannose-derived nitrone with methyl acrylate. Advantages of this newly developed synthesis include the use of economically available materials and reagents, the ease of ...
Du Jian J Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD 21218, - - 2009
This report provides a perspective on metabolic glycoengineering methodology developed over the past two decades that allows natural sialic acids to be replaced with chemical variants in living cells and animals. Examples are given demonstrating how this technology provides the glycoscientist with chemical tools that are beginning to reproduce Mother ...
Gunnarsson Peter - - 2010
OBJECTIVE: We have recently shown that terminal sialic acid residues are essential for alpha(1)-acid glycoprotein (AGP)-induced Ca(2+) mobilization in neutrophils. The aim of the present study was to establish the importance of sialic acid residues on AGP in modulating human neutrophil functions, with emphasis on the generation of reactive oxygen ...
Li Xiaoxin - - 2009
Bovine adenovirus serotype 3 (BAd3) and porcine adenovirus serotype 3 (PAd3) entry into the host cells is independent of Coxsackievirus adenovirus receptor and integrins. The role of sialic acid in BAd3 and PAd3 entry was investigated. Removal of sialic acid by neuraminidase, or blocking sialic acid by wheat germ agglutinin ...
Lewis Amanda L - - 2009
Sialic acids (Sias) are nonulosonic acid (NulO) sugars prominently displayed on vertebrate cells and occasionally mimicked by bacterial pathogens using homologous biosynthetic pathways. It has been suggested that Sias were an animal innovation and later emerged in pathogens by convergent evolution or horizontal gene transfer. To better illuminate the evolutionary ...
Miner-Williams Warren - - 2009
The aim was to compare five techniques commonly used to quantify mucin concentrations in ileal digesta collected from three growing pigs that had been fed a diet in which the sole protein was casein. Ileal mucin output was estimated by the periodic acid-Schiff, ethanol precipitation, and phenol-sulfuric acid methods as ...
Suzuki Kaori - - 2009
Glycomonomers of sialic acid in which the acetamide group at C-5 was converted into two kinds of C=C double bond substituents were prepared and the fully protected glycomonomers were directly polymerized before deprotection steps. Radical polymerization with acrylamide in DMF in the presence of ammonium persulfate and N,N,N',N'-tetramethylethylenediamine proceeded smoothly ...
Reinke Stefan O - - 2009
The key enzyme for the biosynthesis of N-acetylneuraminic acid, from which all other sialic acids are formed, is the bifunctional enzyme UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE). GNE is a highly conserved protein found throughout the animal kingdom. Its highest expression is seen in the liver and placenta. GNE is regulated by ...
Kontou Maria - - 2009
Sialic acids represent a family of 9-carbon acidic amino sugars expressed mainly as terminal monosaccharides on most mammalian glycoconjugates. Sialic acids play an outstanding role during cellular processes, such as development and regeneration, as they are involved in a variety of molecular interactions. Sialic acids are synthesized in the cytosol ...
Almagro-Moreno Salvador - - 2009
Sialic acids comprise a family of nine-carbon ketosugars that are ubiquitous on mammalian mucous membranes. However, sialic acids have a limited distribution among Bacteria and are confined mainly to pathogenic and commensal species. Vibrio pathogenicity island 2 (VPI-2), a 57-kb region found exclusively among pathogenic strains of Vibrio cholerae, contains ...
Johansson Susanne - - 2009
The adenovirus serotype Ad37 binds to and infects human corneal epithelial (HCE) cells through attachment to cellular glycoproteins carrying terminal sialic acids. By use of the crystallographic structure of the sialic acid-interacting domain of the Ad37 fiber protein in complex with sialyllactose, a set of N-acyl modified sialic acids were ...
Takimoto Kazuhiro - - 2009
Previously, we histochemically examined the kidney of the MCC strain of mastomys (Praomys coucha) and found the storage of gangliosides. In the present studies, the lipid-bound sialic acid content of gangliosides in the MCC kidney was about 9- to 14-fold higher than that of the control (MWC strain). In the ...
Siebert Hans-Christian - - 2009
The affinity to sialic acid-containing oligosaccharides of the small-animal lectin SHL-I isolated from the venom of the Chinese bird-hunting spider Selenocosmia huwena is here described for the first time. By a strategic combination of NMR techniques, molecular modeling, and data mining tools it was possible to identify the crucial amino ...
Malicdan May Christine V - - 2009
Distal myopathy with rimmed vacuoles (DMRV)-hereditary inclusion body myopathy (hIBM) is an adult-onset, moderately progressive autosomal recessive myopathy; eventually, affected individuals become wheelchair bound1. It is characterized clinically by skeletal muscle atrophy and weakness, and pathologically by rimmed vacuoles, which are actually accumulations of autophagic vacuoles2, 3, 4, scattered angular ...
Mochel Fanny - - 2009
We performed high-resolution in vitro proton nuclear magnetic resonance spectroscopy on cerebrospinal fluid and urine samples of 44 patients with leukodystrophies of unknown cause. Free sialic acid concentration was increased in cerebrospinal fluid of two siblings with mental retardation and mild hypomyelination. By contrast, urinary excretion of free sialic acid ...
Schauer Roland - - 2009
The sialic acids of the platypus, birds, and reptiles were investigated with regard to the occurrence of N-glycolylneuraminic (Neu5Gc) acid. They were released from tissues, eggs, or salivary mucin samples by acid hydrolysis, and purified and analyzed by thin-layer chromatography, high-performance liquid chromatography, and mass spectrometry. In muscle and liver ...
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