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Meo C D - - 2001
A highly efficient synthesis of the human melanoma associated antigen GD(3) derivative has been described. A key feature of the synthetic approach was the use of sialyl donors that were protected with a C-5 trifluoroacetamide moiety. These sialyl donors gave high yields and excellent alpha-anomeric selectivities in direct glycosylations with ...
Mantey L R - - 2001
Sialic acids comprise a family of terminal sugars essential for a variety of biological recognition systems. N-Propanoylmannosamine, an unphysiological sialic acid precursor, is taken up and metabolized by mammalian cells resulting in oligosaccharide-bound N-propanoylneuraminic acid. N-Propanoylmannosamine, applied to endogenously hyposialylated subclones of the myeloid leukemia HL60 and of the B-cell ...
Lederkremer R M - - 2001
The most important glycoproteins of trypanosomatids are anchored by glycoinositolphospholipids (GIPLs) to their plasma membrane. In addition, free GIPLs have been described, for instance the lipopeptidophosphoglycan (LPPG) which is a major component of the surface of T. cruzi epimastigotes. An inositolphosphoceramide (IPC) is part of the LPPG and of glycoproteins ...
McGowen M M - - 2001
We have chosen E. coli K92, which produces the alternating structure alpha(2-8)neuNAc alpha(2-9)neuNAc as a model system for studying bacterial polysaccharide biosynthesis. We have shown that the polysialyltransferase encoded by the K92 neuS gene can synthesize both alpha(2-8) and alpha(2-9) neuNAc linkages in vivo by 13C-nuclear magnetic resonance analysis of ...
Zanetta J P - - 2001
The fine structural motifs of sialic acids, a frequent terminal monosaccharide of glycans, seem to contain essential biological properties. To identify such subtle structural differences, a reliable method was developed for the qualitative and quantitative identification of sialic acids present in different tissues and fluids. This method involved, after liberation ...
Kaludov N - - 2001
Adeno-associated virus serotype 4 (AAV4) and AAV5 have different tropisms compared to AAV2 and to each other. We recently reported that alpha 2--3 sialic acid is required for AAV5 binding and transduction. In this study, we characterized AAV4 binding and transduction and found it also binds sialic acid, but the ...
Varki A - - 2001
Classic studies suggested that the common mammalian sialic acid N-glycolylneuraminic acid (Neu5Gc) is an oncofetal antigen in humans, being immunogenic in adult humans and yet apparently expressed in human fetuses and tumors. We and others have recently found that the human deficiency of Neu5Gc can be explained by an inactivating ...
Murrell M T - - 2001
Entry and fusion of human parainfluenza virus type 3 (HPF3) requires interaction of the viral hemagglutinin-neuraminidase (HN) glycoprotein with its sialic acid receptor. 4-Guanidino-2,4-dideoxy-2,3-dehydro-N-acetylneuraminic acid (4-GU-DANA; zanamivir), a sialic acid transition-state analog designed to fit the influenza virus neuraminidase catalytic site, possesses antiviral activity at nanomolar concentrations in vitro. We ...
Pedini V - - 2001
In order to elucidate the carbohydrate profile of the mucosa of lamb duodenum, conventional histochemical methods and a panel of 7 labelled lectins were used. In some cases, treatment with sialidase preceeded lectin staining. Carbohydrate histochemistry revealed the presence of sugar residues in the brush border of enterocytes, goblet cells ...
Ylönen A - - 2001
We have recently identified two novel cysteine proteinase inhibitors from the skin of Atlantic salmon (Salmo salar L.), named salmon kininogen and salarin. In preliminary experiments, the proteins were found to be both N- as well as O-glycosylated. In the present study we show that both proteins carry biantennary alpha2,3-sialylated ...
Nakamura Y - - 2001
PURPOSE: We measured the concentration of sialic acid, the terminal component of mucin, in normal diluted human tears. METHODS: Twenty-microliter tear samples were collected from 31 healthy volunteers (average age = 50.7 years) using micropipette after 50 microL instillation of saline. We investigated the correlation of concentration between glycoprotein and ...
Ringenberg M - - 2001
Most microorganisms do not produce sialic acid (sialate), and those that do appear to use a biosynthetic mechanism distinct from mammals. Genetic hybrids of nonpathogenic, sialate-negative laboratory Escherichia coli K-12 strains designed for the de novo synthesis of the polysialic acid capsule from E. coli K1 proved useful in elucidating ...
Mühlenhoff M - - 2001
Poly-alpha-2,8-sialic acid (polysialic acid) is a post-translational modification of the neural cell adhesion molecule (NCAM) and an important regulator of neuronal cell-cell interactions. The synthesis of polysialic acid depends on the two polysialyltransferases ST8SiaII and ST8SiaIV. Understanding the catalytic mechanisms of the polysialyltransferases is critical toward the aim of influencing ...
Bradley S J - - 2001
Glycomimetics are increasingly being recognised as powerful tools in the search for novel compounds that possess useful biological properties. This paper describes our preliminary efforts towards the development of novel mimetics of sialic acid thioglycosides. These sialylmimetics are readily prepared and have been shown, in some instances, to have biological ...
Accili D - - 2001
Direct and indirect staining procedures were developed to characterize sialoglycoconjugates in developing rat submandibular gland. Lectin histochemistry, with and without prior sialidase digestion, combined with differential oxidation and deacetylation procedures was performed in situ. This allowed the expression of sialic acids to be followed during acinar cell development. It was ...
Enns G M - - 2001
Sialuria is a rare inborn error of metabolism in which excessive free sialic acid (N-acetylneuraminic acid, NeuAc) is synthesized. A defect in the feedback inhibition of UDP-N-acetylglucosamine (UDP-GlcNAc) 2-epimerase by the end-product of the sialic acid synthetic pathway, CMP-NeuAc, is the mechanism underlying this overproduction. Recent evidence suggests that sialuria ...
Parillo F - - 2001
Lagomorpha are often used as animal models in reproductive experiments. The aim of the present study was to examine the glycoconjugate modifications occurring mainly in the zona pellucida during oocyte growth in the rabbit and hare, using a battery of lectins combined with sialidase digestion and chemical treatments. This histochemical ...
Accili D - - 2001
Sialoglycoconjugates in rat sublingual gland acinar cells, at different stages of pre- and post-natal development, were investigated in situ with specific lectins and by the selective removal of terminal sialic acids. Cleavage of acetyl substituents sited in the pyranose ring and/or polyhydroxyl side chain was used as an additional means ...
Arao K - - 2001
Two novel type gangliosides CJP2 and CJP3 have been obtained from the feather star Comanthus japonica. On the basis of methylation linkage analysis combined with ammonolysis and other chemical and spectroscopic evidence, the chemical structures of CJP2 and CJP3 were determined to be alpha-9-O-Me-NeuGc-(2-->3)-inositolphosphoceramide and alpha-9-O-Me-NeuGc-(2-->11)-alpha-9-O-Me-NeuGc-(2-->3)-inositolphosphoceramide, respectively. These gangliosides are ...
Bianco A - - 2001
The influenza virus neuraminidase (NA) is essential for viral infection and offers a potential target for antiviral drug development. We prepared a carbocyclic sialic acid analogue, potentially able to inhibit NA. Its structure is an analogue of the transition-state of the reaction catalysed by NA. As starting material, quinic acid ...
Connolly J L - - 2001
Reovirus induces apoptosis in cultured cells and in vivo. Genetic studies indicate that the efficiency with which reovirus strains induce apoptosis is determined by the viral S1 gene, which encodes attachment protein sigma1. However, the biochemical properties of sigma1 that influence apoptosis induction are unknown. To determine whether the capacity ...
Leavell M D - - 2001
The dissociation of metal-ligated sialyllactose and sialyl-N-acetyllactosamine was investigated. Metal-ligand derivatization of the carbohydrate samples with the diethylenetriamine ligand and one of four transition metals [Co(II), Ni(II), Cu(II), Zn(II)] suppressed sialic acid loss in the collision-induced dissociation process. Suppression of sialic acid loss allows sialic acid linkage information to be ...
Powell L D - - 2001
Sialic acids are a family of nine-carbon acidic sugars found at the nonreducing terminus of many glycoconjugates. Sialidases can remove these sugar units selectively from cell surfaces, membranes, or purified glycoconjugates. In this unit, sialidase digestion of purified glycoproteins is described as is treatment of intact cells. The physical properties ...
Tringali C - - 2001
Acidic and neutral sialidases (pH optimum 4.7 and 7.2, respectively) were assayed on human circulating erythrocytes during ageing. The assays were performed on intact erythrocytes and resealed erythrocyte ghost membranes. From young to senescent erythrocytes the acidic sialidase featured a 2.7-fold and 2.5-fold decrease in specific activity when measured on ...
Salomäki P - - 2001
Sialic acid storage disorders, Salla disease (SD) and a severe infantile form of disease (ISSD), are recessively inherited allelic lysosomal storage disorders due to impaired egress of free sialic acid from lysosomes. Fourteen pregnancies at risk of adult-type free sialic acid storage disease, SD, were monitored by sialic acid assays, ...
Manzi A - - 2001
The first step in obtaining a compositional analysis of a glycoconjugate is the release of the individual monosaccharide constituents. Mild acid hydrolysis to release fucosyl residues from glycoconjugates is described in this unit, in addition to mild acid hydrolysis to release sialic acids from glycoconjugates, along with dialysis and column ...
Manzi A E - - 2001
This unit presents methods for assaying sialic acids, reducing sugars, and hexosamines. The BCA assay detects free reducing terminii in sugars released from glycoconjugates by appropriate treatments. Assays employing Ehrlich reagent (DMAB) detect hexosamines and N-acetylhexosamines, including a method for hydrolyzing the glycosidic linkages of the hexosamines and a method ...
Lakshman R - - 2001
This article represents the proceedings of a symposium at the 2000 ISBRA Meeting in Yokohama, Japan. The chairs were Raj Lakshman and Mikihiro Tsutsumi. The presentations were (1) Sialic acid index of apolipoprotein J: A new marker for chronic alcohol consumption, by P. Ghosh and M. R. Lakshman; (2) Microheterogeneity ...
Sumi T - - 2001
N-Glycolylneuraminic acid (Neu5Gc), precious sialic acid which could not be synthesized by a chemical method, occurrs in the body of holothuroidea, Gumi Cucumaria echinata. Gumi contains 85% of total sialic acid, as Neu5Gc, in the body. Neu5Gc was purified from dry powder of the body using Dowex 1-x8 (HCOO* form) ...
Shaw C J - - 2001
Sialic acids are widely found in nature as components of oligosaccharide units in mucins, glycoproteins and other microbial polymers. Existing methods for determining these acids are long, tedious, and not specific. A simple, rapid, and sensitive method for determining the most commonly occurring acids, N-acetylneuraminic and N-glycolylneuraminic acid, using LC-MS ...
Wasylnka J A - - 2001
ASPERGILLUS: fumigatus is a ubiquitous soil fungus that causes invasive lung disease in the immunocompromised host. The structure of the conidial wall has not been well characterized although it is thought that adhesins present on the surface are involved in attachment of the conidia to host lung cells and proteins, ...
Ulloa F - - 2001
We used lectin cytochemistry and confocal microscopy to examine the distribution of sialic acid in epithelial cells. Maackia amurensis lectin and Sambuccus nigra agglutinin were used to detect alpha2,3 and alpha2,6 sialic acid, respectively. In Caco-2, HT-29 5M12, and MCF-7 cells, which express sialic acid mainly in one type of ...
Bianco A - - 2001
The influenza virus neuraminidase (NA) is an enzyme essential for viral infection and offers a potential target for antiviral drug development. We aimed our research at the synthesis of non-carbohydrate molecules able to inhibit NA as transition-state analogues. Aromatic sialic acid analogues (compound 5 and compound 10) were synthesised in ...
Yokoyama S - - 2001
Micellar inhibition effect of gangliosides on a degradation of drug was investigated, where ganglioside G(M1) (GM1), G(D1a) (GD1a) and G(T1b) (GTlb) whose sialic acid residue is one, two and three, respectively, were used. The base-catalyzed isomerization of prostaglandin A(2) (PGA(2)) to prostaglandin B(2) (PGB(2)) was chosen as a model experiment. ...
Creus S - - 2001
Differences in sialic acid content of the hormone have been considered the main determinant of FSH polymorphism. The aim of the present study was to investigate the effect of variations in the oligosaccharide structure of the intrapituitary human FSH (hFSH) glycosylation variants on their intrinsic biological activity. FSH charge isoforms ...
Lawrence S M - - 2001
The addition of sialic acid residues to glycoproteins can affect important protein properties including biological activity and in vivo circulatory half-life. For sialylation to occur, the donor sugar nucleotide cytidine monophospho-sialic acid (CMP-SA) must be generated and enzymatically transferred to an acceptor oligosaccharide. However, examination of insect cells grown in ...
Daali Y - - 2001
Capillary zone electrophoresis was applied to separate caseinoglycomacropeptide glycoforms and characterize microheterogeneity of the glycopeptide. Particular attention was paid to the sialic acid content in caseinoglycomacropeptide obtained through different manufacturing processes. A chemometric approach was used to simultaneously study effects of acid concentration, hydrolysis time and temperature on sialic acid ...
Okada T - - 2001
Prostate-specific antigen (PSA) is a glycosylated chymotrypsin-like serine protease and is found mainly in prostatic tissue and seminal fluid. We purified two forms of PSA (PSA-A and PSA-B) from human seminal fluid with pI values of approx. 7.2 and approx. 6.9, respectively. To characterize the N-glycans of the two isoforms, ...
Keppler O T - - 2001
N-Acetylneuraminic acid is the most prominent sialic acid in eukaryotes. The structural diversity of sialic acid is exploited by viruses, bacteria, and toxins and by the sialoglycoproteins and sialoglycolipids involved in cell-cell recognition in their highly specific recognition and binding to cellular receptors. The physiological precursor of all sialic acids ...
Yu Z - - 2001
The sialic acid-binding immunoglobulin-like lectins (siglecs) represent a recently defined distinct subset of the immunoglobulin superfamily. By using the Src homology 2 (SH2)-domain-containing protein tyrosine phosphatase SHP-1 as bait in a yeast two-hybrid screen, we have identified a new member of the mouse siglec family, mSiglec-E. The mSiglec-E cDNA encodes ...
Roy D - - 2001
Molecular dynamics simulation of ganglioside GD1a attached to the upper layer of a fully hydrated lipid bilayer of dimyristoyl phosphatidyl choline (DMPC) at room temperature under periodic boundary conditions was performed. The time average conformation of GD1a reveals that the terminal sialic acid is more exposed into the solvent than ...
Zdebska E - - 2001
Band 3 and PAS-1 (a dimer of glycophorin A) from erythrocyte membranes of three children with congenital disorder of glycosylation, type Ia (CDG-Ia), aged 1 month, 3 years and 10 years respectively, were examined by a new technique that allowed determination of carbohydrate molar composition of glycoproteins separated by sodium ...
Burke S D - - 2001
[figure: see text] Formal synthesis of the naturally occurring deaminated sialic acid KDN, a potential oncofetal antigen, has been accomplished in 45% overall yield via a novel ketalization/ring-closing metathesis sequence. The rapid introduction of all oxygen functionality in a completely stereocontrolled manner exploited a rigid 6,8-dioxabicyclo[3.2.1]oct-2-ene ring system. This general ...
Otsubo N - - 2001
Novel ganglioside GM4 analogues, which contain N-deacetylated or lactamized sialic acid instead of usual N-acetylneuraminic acid, were synthesized in a highly efficient manner. (Methyl 4,7,8,9-tetra-O-acetyl-3,5-dideoxy-5-trifluoroacetamido-D-glycero-alpha-D-galacto-2-nonulopyranosylonate)-(2-->3)-4,6-di-O-acetyl-2-O-benzoyl-D-galactopyranosyl trichloroacetimidate was coupled with 2-(tetradecyl)hexadecanol to give the desired beta-glycoside in high yield. Successive O- and N-deacylation, and saponification of the methyl ester group afforded ...
Inoue S - - 2001
We found that the hepatopancreas of oyster, Crassostrea virginica, contained a sialidase capable of releasing Neu5Gc from the novel polysialic acid chain (-->5-O(glycolyl)Neu5Gcalpha2-->)n more efficiently than from the conventional type of polysialic acid chains, (-->8Neu5Acalpha2-->)n, or (-->8Neu5Gcalpha2-->)n. We have partially purified this novel sialidase and compared its reactivity with that ...
Shori D K - - 2001
Destruction of the lungs as a consequence of recurrent infections with microorganisms such as Pseudomonas aeruginosa remains the underlying cause of most morbidity and mortality in cystic fibrosis (CF). We have hypothesized that changes in the glycosylation of key tracheal mucins such as MUC5B and MUC7 might increase the risk ...
Ferens-Sieczkowska M - - 2001
Haptoglobin is one of acute phase glycoproteins often used as markers in glycopathology studies. In this work the oligosaccharide structures of haptoglobin from 'healthy' subjects have been studied in detail, taking into consideration the possible dependence of glycosylation on the phenotype. About 75% of charged haptoglobin glycans were of biantennary ...
Isitmangil T - - 2001
It is known that tissue and serum sialic acid levels may be altered by malignant transformation. In this study, sialic acid levels were determined in bronchoalveolar lavage fluid (BAL) and serum in two groups of patients with lung cancer and non-malignant diseases of the lung. Colorimetric methods were used for ...
Millar J S - - 2001
Sialic acids are a family of amino sugars that are commonly found as terminal oligosaccharide residues on glycoproteins and glycolipids. Plasma lipoproteins are sialylated on their apolipoprotein and glycolipid constituents. The function of sialic acid on apolipoproteins is not completely understood but has been associated with secretion, lipid-binding, and plasma ...
Varki A - - 2001
The surface of all mammalian cells is covered with a dense and complex array of sugar chains, which are frequently terminated by members of a family of molecules called sialic acids. One particular sialic acid called N-glycolylneuraminic acid (Neu5Gc) is widely expressed on most mammalian tissues, but is not easily ...
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