A detailed study of the periodate oxidation of sialic acids in glycoproteins.
TL;DR: Periodate oxidation of terminalN-acetyl- andN-glycoloylneuraminic acid residues in the mucins from edible bird nest substance and pig submandibular gland can be carried out under conditions which exclusively give rise to the formation of the C-7 analogues of these sialic acids.
Abstract: Periodate oxidation of terminalN-acetyl- andN-glycoloylneuraminic acid residues in the mucins from edible bird nest substance and pig submandibular gland, respectively, can be carried out under conditions which exclusively give rise to the formation of the C-7 analogues of these sialic acids. In contrast, the C-8 compounds can be obtained in a maximum yield of about 40%. Under identical conditions,N-glycoloylneuraminic acid is oxidized about 1.5 times faster than theN-acetylated derivative. After release of the sialic acids by acid hydrolysis, the characterization of the oxidation products was carried out by TLC, by GLC and GLC-MS of the corresponding pertrimethylsilyl derivatives, and by 500-MHz1H-NMR spectroscopy. In addition, molar response factors for GLC analysis and extinction coefficients in the orcinol/Fe3+/HCl assay were determined.
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TL;DR: The I- type lectins are a subset of the immunoglobulin superfamily that are capable of carbohydrate-protein interactions and there are I-type lectins recognizing sialic acids, other sugars and glycosaminoglycans.
238 citations
212 citations
TL;DR: The results suggest that this method of conjugation to a carrier protein may be a useful strategy to improve the immunogenicity of the type III group B Streptococcus polysaccharide in human subjects.
Abstract: The native capsular polysaccharide of type III group B Streptococcus elicits a specific antibody response in only 60% of nonimmune human subjects. To enhance the immunogenicity of this polysaccharide, we coupled the type III polysaccharide to tetanus toxoid. Prior to coupling, aldehyde groups were introduced on the polysaccharide by controlled periodate oxidation, resulting in the conversion of 25% of the sialic acid residues of the polysaccharide to residues of the 8-carbon analogue of sialic acid, 5-acetamido-3,5-dideoxy-D-galactosyloctulosonic acid. Tetanus toxoid was conjugated to the polysaccharide by reductive amination, via the free aldehyde groups present on the partially oxidized sialic acid residues. Rabbits vaccinated with the conjugate vaccine produced IgG antibodies that reacted with the native type III group B streptococcal polysaccharide (3/3 rabbits), while rabbits immunized with the unconjugated type III polysaccharide failed to respond (0/3 rabbits). Sera from animals receiving conjugate vaccine opsonized type III group B streptococci for phagocytic killing by human peripheral blood leukocytes, and protected mice against lethal challenge with live type III group B streptococci. The results suggest that this method of conjugation to a carrier protein may be a useful strategy to improve the immunogenicity of the type III group B Streptococcus polysaccharide in human subjects.
209 citations
TL;DR: Sialidases (neuraminidases), which liberate sialic acids from cellular compounds, had been known from very early on from studies with influenza viruses, and are studied because of their significance in development and, for instance, in cancer.
Abstract: Sialic acids are cytoprotectors, mainly localized on the surface of cell membranes with multiple and outstanding cell biological functions. The history of their structural analysis, occurrence, and functions is fascinating and described in this review. Reports from different researchers on apparently similar substances from a variety of biological materials led to the identification of a 9-carbon monosaccharide, which in 1957 was designated "sialic acid." The most frequently occurring member of the sialic acid family is N-acetylneuraminic acid, followed by N-glycolylneuraminic acid and O-acetylated derivatives, and up to now over about 80 neuraminic acid derivatives have been described. They appeared first in the animal kingdom, ranging from echinoderms up to higher animals, in many microorganisms, and are also expressed in insects, but are absent in higher plants. Sialic acids are masks and ligands and play as such dual roles in biology. Their involvement in immunology and tumor biology, as well as in hereditary diseases, cannot be underestimated. N-Glycolylneuraminic acid is very special, as this sugar cannot be expressed by humans, but is a xenoantigen with pathogenetic potential. Sialidases (neuraminidases), which liberate sialic acids from cellular compounds, had been known from very early on from studies with influenza viruses. Sialyltransferases, which are responsible for the sialylation of glycans and elongation of polysialic acids, are studied because of their significance in development and, for instance, in cancer. As more information about the functions in health and disease is acquired, the use of sialic acids in the treatment of diseases is also envisaged.
184 citations
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TL;DR: The I- type lectins are a subset of the immunoglobulin superfamily that are capable of carbohydrate-protein interactions and there are I-type lectins recognizing sialic acids, other sugars and glycosaminoglycans.
174 citations
References
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TL;DR: The conditions for the periodate oxidation and subsequent borohydride reduction of gangliosides were investigated with regard to the yield of C7- and C8-analogues of NeuNAc and the integrity of other monosaccharide chain and products were obtained which closely resemble the native gangLiosides.
129 citations
TL;DR: The chapter describes various tools for the analysis of sialic acids ranging from assays that can easily be handled and are in wide use, to techniques that require expensive equipment and specialists for the interpretation of analytical data.
Abstract: Publisher Summary Since 1978, when the last review on the analysis of sialic acids appeared in the series, interest in these compounds has increased, as their involvement in the biological functions of many different molecules and cells became evident Sialic acids have also gained increasing attention in pathological processes, example, sialidosis, in which sialoglycoconjugates accumulate because of a lack of sialidase Sensitive and reliable techniques are necessary for the qualitative and quantitative analysis of sialic acids, which are present in biological materials only in low amounts The chapter discusses isolation and purification of sialic acids in detail There is also a discussion on the colorimetric analysis of sialic acids The discussion of chromatographic analyses of sialic acids includes thin-layer chromatography, high-performance liquid chromatography, gas-liquid chromatography, gas-liquid chromatography-mass spectrometry, high-performance liquid chromatography-mass spectrometry, fast atom bombardment mass spectrometry, and nuclear magnetic resonance spectroscopy The chapter describes various tools for the analysis of sialic acids ranging from assays that can easily be handled and are in wide use, to techniques that require expensive equipment and specialists for the interpretation of analytical data
116 citations
TL;DR: A number of O-acetylated N-acylneuraminic acids isolated from submandibular glands of cow and horse and from horse erythrocytes, have been characterized by mass spectrometry on the basis of the typical fragmentation patterns of the pertrimethylsilyl derivatives of the methyl esters of the compounds.
100 citations
01 Jan 1982
TL;DR: For the structural analysis of the carbohydrate chains of glycoconjugates, oligosaccharides and polysaccharides, the introduction of gas-liquid chromatography (g.l.c)/m.s. has proved to be of great importance.
Abstract: For the structural analysis of the carbohydrate chains of glycoconjugates, oligosaccharides and polysaccharides, the introduction of gas-liquid chromatography (g.l.c.) and later on of gas-liquid chromatography combined with mass spectrometry (g.l.c./m.s.) has proved to be of great importance. As has been summarized in several comprehensive reviews, many protecting groups are in use to prepare volatile sugar derivatives (Bishop 1964, Clamp et al 1971, Dutton 1973, 1974).
85 citations
TL;DR: Sialic acids were analyzed as per-O-trimethylsilylated compounds by gas-liquid chromatography/mass spectrometry either on electron or chemical ionization by isobutane to identify the seven different sialic acid derivatives.
26 citations