Search Results
Results 201 - 250 of 2012
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Agustí Rosalía - - 2007
The mucin-like glycoproteins of Trypanosoma cruzi have novel O-linked oligosaccharides that are acceptors of sialic acid in the trans-sialidase (TcTS) reaction. The transference of sialic acid from host glycoconjugates to the mucins is involved in infection and pathogenesis. The O-linked chains may contain galactofuranose in addition to the acceptor galactopyranose ...
Popa Iuliana - - 2007
The presence of gangliosides containing de-N-acetylated sialic acids in human tissues has been so far shown by using mouse monoclonal antibodies specific for the de-N-acetylated forms, but the isolation and chemical characterization of such compounds have not yet been performed. Since indirect evidence suggested that de-N-acetylGD3 ganglioside could be present ...
Chokhawala Harshal A - - 2007
Sialidases, or neuraminidases, are enzymes that cleave terminal sialic acid (Sia) residues from complex sialic acid-containing structures. They have been found in many animals and microorganisms and are important in various physiological and pathological processes. In order to understand the biological significance of diverse sialidases, it is important to study ...
Gagiannis Daniel - - 2007
Sialic acids are widely expressed as terminal carbohydrates on glycoconjugates of eukaryotic cells. They are involved in a variety of cellular functions, such as cell adhesion or signal recognition. The key enzyme of sialic acid biosynthesis is the bifunctional UDP-N-acetylglucosamine-2-epimerase/N-acetylmannosamine kinase (GNE), which catalyzes the first two steps of sialic ...
Teuton Jeremy R - - 2007
Herpes simplex virus type 1 (HSV-1) envelope proteins are posttranslationally modified by the addition of sialic acids to the termini of the glycan side chains. Although gC, gD, and gH are sialylated, it is not known whether sialic acids on these envelope proteins are functionally important. Digestion of sucrose gradient ...
Warwas Mark L - - 2007
Aspergillus fumigatus is an opportunistic fungal pathogen that causes a life-threatening invasive fungal disease (invasive aspergillosis, IA) in immunocompromised individuals. The first step of pathogenesis is thought to be the attachment of conidia to proteins in lung tissue. Previous studies in our laboratory have shown that conidia adhere to basal ...
Scillitani Giovanni - - 2007
Mucins in the gastrointestinal tract of Rhinolophus ferrumequinum were investigated by histochemistry and lectin histochemistry to evaluate morphofunctional variations of different regions and their possible physiological and evolutionary implications. Histochemical methods included periodic acid-Schiff (PAS), Alcian blue (AB) at pH 2.5 and 1.0 and high-iron-diamine AB pH 2.5. Binding of ...
Hannuksela Minna L - - 2007
Alcohol and alcohol-related diseases have become a major cause of death in Western countries. The most sensitive and specific of the commonly used biomarkers of alcohol intake are carbohydrate-deficient transferrin (CDT), and the combination of gamma-glutamyltransferase (GGT) and CDT. Other widely used laboratory markers are GGT, mean corpuscular volume of ...
Laughlin Scott T - - 2007
Metabolic labeling of glycans with a bioorthogonal chemical reporter such as the azide enables their visualization in cells and organisms as well as the enrichment of specific glycoprotein types for proteomic analysis. This process involves two steps. Azido sugars are fed to cells or organisms and integrated by the glycan ...
Oztürk Leyla Koç - - 2007
In recent years, sialic acid is considered to be a possible marker for cardiovascular diseases. The aim of this study was to investigate the effect of two different treatment periods of fenofibrate (CAS 49562-28-9) on serum, heart and liver sialic acid levels in experimental hypercholesterolemia. Serum, heart and liver total ...
Wang Bing - - 2007
BACKGROUND: Sialic acid (N-acetylneuraminic acid), a component of gangliosides and sialylglycoproteins, may be a conditional nutrient in early life because endogenous synthesis is limited. The aim of this study was to investigate the metabolic fate of intravenously administrated N-acetylneuraminic acid-6-14C (sialic acid) in piglets. METHOD: Three-day-old male domestic piglets (Sus ...
Yashpal Madhu - - 2007
Glycoproteins (GPs) elaborated by the buccal epithelium of the catfish, Rita rita, were analysed by a range of histochemical methods. These included methods for the characterization and simultaneous visualization of GPs with oxidizable vicinal diols, with O-acyl sugars, with O-sulphate esters and with sialic acid residues with and without O-acyl ...
Stuart Amanda D - - 2007
Feline calicivirus (FCV) is a major causative agent of respiratory disease in cats. It is also one of the few cultivatable members of the family Caliciviridae. It has recently been reported that FCV binding is in part due to interaction with junction adhesion molecule-A. This report describes the characterization of ...
Reyes-Leyva Julio - - 2007
A mutation coding for the amino acid change E335 to K is frequently found in the hemagglutinin-neuraminidase (HN) gene of Urabe AM9 mumps viruses isolated during post-vaccination meningitis cases. To identify if this mutation modifies the biological activities of the HN glycoprotein, two variants of Urabe AM9 vaccine differing at ...
Neres João - - 2007
Benzoic acid and pyridine derivatives inhibit recombinant trans-sialidase from Trypanosoma cruzi with I50 values between 0.4 and 1mM. The best compounds, 4-acetylamino-3-hydroxymethylbenzoic acid and 5-acetylamino-6-aminopyridine-2-carboxylic acid, provide new leads to inhibitors not containing the synthetically complex sialic acid structure. The weak inhibition by such compounds contrasts with their much stronger ...
Pon Robert A - - 2007
The inherent promiscuity of the polysialic acid (PSA) biosynthetic pathway has been exploited by the use of exogenous unnatural sialic acid precursor molecules to introduce unnatural modifications into cellular PSA, and has found applications in nervous system development and tumor vaccine studies. The sialic acid precursor molecules N-propionyl- and N-butanoyl-mannosamine ...
Bratosin Daniela - - 2007
Sialic acids from the erythrocyte (RBC) membrane of a patient suffering from polycythemia vera, a malignant orphan disorder of hematopoietic cells, was studied using GC/MS. We found that the sialic acid diversity of these membranes was drastically reduced since only four entities were identified: Neu5Ac (91.5%) and its 1,7 lactone ...
van der Ham Maria - - 2007
BACKGROUND: The main purpose for measuring urinary free sialic acid (FSA) is to diagnose sialic acid (SA) storage diseases. Elevated amounts of conjugated sialic acid (CSA) are observed in several diseases indicating the need to quantify CSA as well. A LC-MS/MS method for quantification of FSA and total sialic acid ...
Vionnet Justine - - 2006
The polysialyltransferase of Escherichia coli K92 catalyzes the transfer of sialic acid from CMP-sialic acid to a growing chain of polysialic acid at the nonreducing end. The enzyme encoded by the neuS gene is membrane-associated and has been suggested to be organized within a complex of several proteins encoded by ...
Campo S - - 2007
FSH is synthesized and secreted in multiple molecular forms with different oligosaccharide structures which are needed for full expression of biological activity. GnRH and sex steroids modulate oligosaccharide structure and composition. In the present study we have assessed the carbohydrate complexity and proportion of circulating FSH isoforms during puberty, aging ...
Niimura Yukio - - 2006
Four unidentified acidic glycolipids (X3-X6) were isolated from the kidney of the Pacific salmon on an anion exchange column and by high performance liquid chromatography using a silica bead (Iatrobeads) column. Based on methylation analysis, chemical and enzymatic degradation, proton nuclear magnetic resonance spectroscopy and mass spectrometry, the glycon structure ...
Urbaniak Michael D - - 2006
Galactose metabolism is essential for the survival of Trypanosoma brucei, the etiological agent of African sleeping sickness. T. brucei hexose transporters are unable to transport galactose, which is instead obtained through the epimerization of UDP-glucose to UDP-galactose catalyzed by UDP-glucose 4'-epimerase (galE). Here, we have characterized the phenotype of a ...
Gagiannis Daniel - - 2007
Sialic acids play an important role during development, regeneration and pathogenesis. The precursor of most physiological sialic acids, such as N-acetylneuraminic acid is N-acetyl-D-mannosamine. Application of the novel N-propanoylmannosamine leads to the incorporation of the new sialic acid N-propanoylneuraminic acid into cell surface glycoconjugates. Here we analyzed the modified sialylation ...
Johansson Susanne M C - - 2007
Adenovirus type 37 is one of the main causative agents of epidemic keratoconjunctivitis. In a series of publications, we have reported that this virus uses sialic acid as a cellular receptor. Here we demonstrate in vitro that on a molar basis, multivalent sialic acid conjugated to human serum albumin prevents ...
Wu Zhijian - - 2006
Recombinant adeno-associated viruses (AAVs) are promising vectors in the field of gene therapy. Different AAV serotypes display distinct tissue tropism, believed to be related to the distribution of their receptors on target cells. Of the 11 well-characterized AAV serotypes, heparan sulfate proteoglycan and sialic acid have been suggested to be ...
Steenbergen Susan M - - 2006
O acetylation at carbon positions 7 or 9 of the sialic acid residues in the polysialic acid capsule of Escherichia coli K1 is catalyzed by a phase-variable contingency locus, neuO, carried by the K1-specific prophage, CUS-3. Here we describe a novel method for analyzing polymeric sialic acid O acetylation that ...
Patel Dhara - - 2006
beta-amyloid (Abeta) is the primary protein component of senile plaques in Alzheimer's disease and is believed to be associated with neurotoxicity in the disease. We and others have shown that Abeta binds with relatively high affinity to clustered sialic acid residues on cell surfaces and that removal of cell surface ...
Aula Nina - - 2006
Free sialic acid storage disorders, Salla disease (SD) and Infantile sialic acid storage disease (ISSD), are lysosomal storage diseases due to impaired function of a sialic acid transporter, sialin, at the lysosomal membrane. Several mutations of the sialin gene, SLC17A5, are known, leading either to the severe neonatal/infantile disease or ...
Otto Vivianne I - - 2006
Intercellular adhesion molecule-1 (ICAM-1) is a heavily N-glycosylated transmembrane protein comprising five extracellular Ig-like domains. The soluble isoform of ICAM-1 (sICAM-1), consisting of its extracellular part, is elevated in the cerebrospinal fluid of patients with severe brain trauma. In mouse astrocytes, recombinant mouse sICAM-1 induces the production of the CXC ...
Reneer Dexter V - - 2006
Anaplasma phagocytophilum, the aetiologic agent of human granulocytic anaplasmosis, is an obligate intracellular bacterium that colonizes neutrophils and neutrophil precursors. The granulocytotropic bacterium uses multiple adhesins that cooperatively bind to the N-terminal region of P-selectin glycoprotein ligand-1 (PSGL-1) and to sialyl Lewis x (sLe(x)) expressed on myeloid cell surfaces. Recognition ...
Johnson Daniel - - 2006
Voltage-gated sodium channels (Nav) are complex glycoproteins comprised of an alpha subunit and often one to several beta subunits. We have shown that sialic acid residues linked to Nav alpha and beta1 subunits alter channel gating. To determine whether beta2-linked sialic acids similarly impact Nav gating, we co-expressed beta2 with ...
Alonso Edurne - - 2006
The presence of mannose (Man) in the glycoconjugates of primordial germ cells (PGCs) of Xenopus embryos was elucidated by lectin histochemistry with Concanavalin A (Con A) and snowdrop (Galanthus nivalis) bulb lectin (GNA), in combination with deglycosylative pretreatments: beta-elimination, which removes O-linked oligosaccharides, and incubation with Peptide N glycosidase F ...
Inoue Sadako - - 2006
KDN is an abbreviation for 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid, and its natural occurrence was revealed in 1986 by a research group including the present authors. Since sialic acid was used as a synonym for N-acylneuraminic acid at that time, there was an argument if this deaminated neuraminic acid belongs to the family ...
Inoue Sadako - - 2006
KDN (Deaminoneuraminic acid, or deaminated neuraminic acid) is a minor but biosynthetically independent member of the sialic acid. Human occurrence of KDN has already been established, although its level is so little that it is often undetectable by conventional sialic acid analysis. Elevated expression of KDN in fetal cord blood ...
Haselhorst Thomas - - 2006
CMP-Kdn synthetase catalyses the reaction of sialic acids (Sia) and CTP to the corresponding activated sugar nucleotide CMP-Sia and pyrophosphate PP( i ). Saturation Transfer Difference (STD) NMR spectroscopy has been employed to investigate the sub-structural requirements of the enzyme's binding domain. Sialylnucleoside mimetics, where the sialic acid moiety has ...
Florea Doina - - 2006
Eggs from Amphibia are surrounded by several layers of jelly that are needed for proper fertilization. Jelly coat is composed of highly glycosylated mucin-type glycoproteins containing up to 60% of carbohydrates, which display a remarkable species-specificity. This material obtained from Triturus alpestris was submitted to reductive beta-elimination and the released ...
Schoenhofen Ian C - - 2006
Flagellin glycosylation is a necessary modification allowing flagellar assembly, bacterial motility, colonization, and hence virulence for the gastrointestinal pathogen Helicobacter pylori [Josenhans, C., Vossebein, L., Friedrich, S., and Suerbaum, S. (2002) FEMS Microbiol. Lett., 210, 165-172; Schirm, M., Schoenhofen, I.C., Logan, S.M., Waldron, K.C., and Thibault, P. (2005) Anal. Chem., ...
Wang Bing - - 2006
ST8Sia IV (polysialyltransferase IV gene) encodes a key enzyme that is required for polysialic acid synthesis. Polysialic acid is a component of the neural cell adhesion molecule and is necessary for synaptic plasticity of neural cells. We characterized 5.3 kb of pig ST8Sia IV cDNA and determined its expression profile ...
Lehmann F - - 2006
Sialic acids consist of a family of acidic nine-carbon sugars that are typically located at the terminal positions of a variety of glycoconjugates. Naturally occurring sialic acids show an immense diversity of structure, and this reflects their involvement in a variety of biologically important processes. One such process involves the ...
Cinar K - - 2006
The wall of the digestive tract is composed of the tunica mucosa, tunica muscularis and tunica serosa. Lamina-submucosa separation or any glands were not observed in tunica mucosa. Goblet cells were determined to constitute a much larger reserve at digestive tract mucosa. Histochemical analysis of the intestine of flower fish ...
Gulesserian T - - 2007
BACKGROUND: Down syndrome (DS, trisomy 21) is the most common genetic cause of mental retardation. A large series of biochemical defects have been observed in fetal and adult DS brain that help in unraveling the molecular mechanisms underlying mental retardation. AIMS: As sialylation of glycoconjugates plays an important role in ...
Yu Hai - - 2006
[reaction: see text] beta-D-Galp-(1-->9)-D-KDN, a disaccharide component of the cell wall of Streptomyces sp. MB-8, was synthesized from beta-D-Galp-(1-->6)-D-Manp and pyruvate using a sialic acid aldolase. The obtained KDN-containing compound was a novel acceptor for bacterial sialyltransferases. Unusual alpha2,3- and alpha2,6-linked sialyltrisaccharides and a tetrasaccharide were synthesized using a one-pot ...
Yasukawa Zenta - - 2006
Serum glycoproteins are involved in various biologic activities, such as the removal of exogenous antigens, fibrinolysis, and metal transport. Some of them are also useful markers of inflammation and disease. Although the amount of sialic acid increases following inflammation, little attention has been paid to the presence of linkage-specific epitopes ...
Xiang Shu Li - - 2006
Guillain-Barré syndrome (GBS) is an autoimmune neuropathy that often follows C. jejuni infection. Sialic acid (N-acetylneuraminic acid, NANA) is a common constituent of lipooligosaccharide (LOS). The molecular mimicry between C. jejuni LOS and human peripheral nerve gangliosides is believed to play an important role in the pathogenesis of GBS. The ...
Crich David - - 2006
The formation of sialic acid glycosides with a thiosialic acid derivative, diphenyl sulfoxide, and trifluoromethanesulfonic anhydride is reported. With an excess of diphenyl sulfoxide, glycal formation can be completely suppressed and excellent yields are obtained for coupling to a wide range of primary, secondary, and tertiary acceptors.
Okazaki Toshio - - 2006
To clarify the regulatory mechanism of the rapid changes in the hemocyte density in the silkworm, Bombyx mori, during ecdysis, we evaluated the relationship between the hemocyte density and the incidence of apoptosis during this stage. We also evaluated the role of the sugar chains on the adhesion of hemocytes ...
Useh N M - - 2006
The erythrocyte surface sialic acid levels of 200 apparently healthy indigenous Nigerian poultry species (pigeons, guinea fowls, ducks and chickens, n = 50 for each species) presented for slaughter at a poultry abattoir in Zaria, Nigeria was determined. Other parameters determined were packed cell volume (PCV) and plasma total protein ...
Natsuki Jun - - 2006
A practical and convenient method for discriminating between the presence and the absence of sialic acid in carbohydrate chains of glycoproteins was devised using paramagnetic beads and two lectins, Sambucus sieboldiana lectin (SSA) and Ricinus communis agglutinin (RCA120). The glycoproteins of transferrin or thyroglobulin were firstly captured to paramagnetic beads ...
Rinninger Andreas - - 2006
Infections by mouse hepatitis viruses result in disease of the liver, the gastrointestinal tract, respiratory tract, and the central nervous system. Coronaviruses related to mouse hepatitis virus express a hemagglutinin-esterase surface glycoprotein, which specifically hydrolyses either 5-N-acetyl-4-O-acetyl neuraminic acid (Neu4,5Ac(2)) or 5-N-acetyl-9-O-acetyl neuraminic acid (Neu5,9Ac(2)). Moreover, these sialic acids represent ...
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