Showing papers on "Sialic acid published in 1970"
TL;DR: The apparent location of the glycosyltransferases in the Golgi apparatus suggests that these enzymes may be involved in terminating the synthesis of plasma glycoproteins by the liver during secretion, and may possibly be required for secretion of these proteins.
579 citations
TL;DR: The GLC method has been applied to analysis of the total brain ganglioside content of several species, and a general trend was observed toward decreasing levels in the lower vertebrates.
328 citations
TL;DR: A highly purified glycopeptide with potent phytohemagglutinin (PHA) receptor site activity has been isolated from human erythrocyte membranes, showing that the inner core sugars can influence PHA-inhibitory activity.
319 citations
TL;DR: In this paper, the survival time in plasma of incompletely desialylated ceruloplasmin, labeled with 64Cu or tritium, was studied in the rat and it was shown that removal of less than 20% of the terminal sialic acid, with consequent exposure of the penultimate galactosyl residues, resulted in the rapid disappearance from the circulation of more than 50% of injected dose.
169 citations
164 citations
TL;DR: Preliminary evidence argues that the carbohydrate moiety covalently bound to different virus-specified membrane proteins may be specified principally by the host.
Abstract: A comparison has been made of the membrane glycoproteins and glycopeptides from two enveloped viruses, Sindbis virus and vesicular stomatitis virus (VSV). Glycopeptides isolated from Sindbis virus and VSV grown in the same host appear to differ principally in the number of sialic acid residues per glycopeptide; when sialic acid is removed by mild acid treatment, the glycopeptides of the two viral proteins are indistinguishable by exclusion chromatography. Preliminary evidence argues that the carbohydrate moiety covalently bound to different virus-specified membrane proteins may be specified principally by the host.
143 citations
TL;DR: Eleven different ganglosides from the bovine tissues and five gangliosides from human spleen were identified and differ in their content of sialic acid.
Abstract: The gangliosides from bovine spleen and kidney as well as human spleen, were extracted from the tissues. The carbohydrate-portion of the gangliosides was characterized. Bovine spleen gangliosides and those isolated from bovine kidney contained the same sialo-oligosaccharide moieties. Eleven different ganglosides from the bovine tissues and five gangliosides from human spleen were identified. They are derived from lactose, ganglio-N-triose, ganglio-N-tetraose, lacto-N-neotetraose or lacto-N-tetraose and differ in their content of sialic acid. Gangliosides from human tissue contain N-acetyl-neuraminic acid only. The sialic acid of the gangliosides from bovine spleen consist of either N-acetyl-neuraminic acid, N-glycolyl-neuraminic acid or both.
136 citations
TL;DR: Synthesis of the fucose-containing glycopeptide in vitro, using uridine-diphosphate-N-acetyl-d-glucosamine-1-14C and 3H-serine, showed a 2- to 3-fold decrease in the incorporation of the labels by rough endoplasmic reticulum prepared from vitamin A-deficient animals as compared with normal animals.
115 citations
TL;DR: The membrane protein of Sindbis virus is a glycoprotein, containing about 14% by weight carbohydrate, and the compounds present include glucosamine, mannose, galactose, fucose and sialic acid.
101 citations
TL;DR: The membrane of the Sindbis virus (an arbovirus) is structurally simple; it is composed of lipids and a single glycoprotein of molecular weight estimated at 53,000 daltons.
100 citations
TL;DR: The earlier resolution of preparations of bovine pancreatic deoxyribonuclease into two active fractions by chromatography on sulfoethyl-Sephadex has been improved through the use of columns of phosphocellulose.
TL;DR: A procedure is described for the preparation of Tay-Sachs ganglioside specifically labeled in the sialic acid portion of the molecule, which was isolated and selectively degraded with bacterial neuraminidase and rat liver beta-galactosidase.
TL;DR: A survey of the walls of over 80 bacterial species has been carried out using chromatographic and colorimetric techniques to demonstrate the presence of 2-keto-3-deoxy-octonic acid (KDO) and or sialic acid.
Abstract: SUMMARY: A survey of the walls of over 80 bacterial species has been carried out using chromatographic and colorimetric techniques to demonstrate the presence of 2-keto-3-deoxy-octonic acid (KDO) and or sialic acid. In most Gram-negative bacteria KDO but not sialic acid was found in the wall, whereas the walls of Gram-positive bacteria contained neither compound.
TL;DR: The glycoproteins and/or glycolipids of the intact L cell and surface membrane are quite variable, and some of the monosaccharides appeared to have a fairly constant molar ratio, one to the other.
TL;DR: The amount of sialoglycoproteins expressed as μmol of sIALic acid per g of lipid‐free residue remained fairly constant in developing rat brain but the activity of various enzymes which may be involved in glycoprotein metabolism varied in an inconstant fashion during the period of development.
Abstract: — The amount of sialoglycoproteins expressed as μmol of sialic acid per g of lipid-free residue remained fairly constant in developing rat brain. However, the activity of various enzymes which may be involved in glycoprotein metabolism varied in an inconstant fashion during the period of development. The specific activity of a neuraminidase increased, N-acetyl-β-glucosaminidase remained relatively constant, while the specific activities of α-mannosidase and α-fucosidase decreased.
TL;DR: A neuraminidase and a neuraminIDase-like factor (NLF) were demonstrated for the first time in acrosomes of rabbit, bull, hamster, ram and human spermatozoa, and the effect of neuraminidsase and NLF on this substrate was not duplicated by trypsin, α-chymotrypsins, pronase, lysozyme, hyaluronidase or detergents.
TL;DR: Both the sialoglycoproteins and the gangliosides occur in highest concentration in areas predominating in neuronal cell bodies (cerebral grey, cerebellar grey, caudate nucleus) and the lowest concentrations are found in those areas, consisting largely of myelinated fibre tracts and glial cells.
Abstract: — Sialoglycoproteins and gangliosides were characterized in various bovine brain regions by determining the amount of sialic acid. Expressed per g dry weight, the gangliosidic sialic acid ranged from 11·20 to 1·93 μmol and the glycoprotein sialic acid from 8·93 to 1·84 μmol in grey and white matter respectively (values not corrected for incomplete release and breakdown during hydrolysis). Both the sialoglycoproteins and the gangliosides occur in highest concentration in areas predominating in neuronal cell bodies (cerebral grey, cerebellar grey, caudate nucleus). The lowest concentrations are found in those areas, consisting largely of myelinated fibre tracts and glial cells (pons, medulla, corpus callosum, cerebral white). Relative to the gangliosides the sialoglycoproteins are somewhat more concentrated in white matter.
The sialidase activity was investigated with endogenous substrate as well as with additional gangliosides or sialoglycopeptides. In all conditions the activity was much greater in grey matter than in white matter. The regional sialidase distribution more or less parallels the distribution of sialic acid in the various regions. At high substrate level the sialoglycopeptides inhibit the sialidase activity. There are indications that gangliosides are a far better substrate for brain sialidase than glycoproteins or glycopeptides. The possible significance of this phenomenon is discussed.
TL;DR: A quantitative analysis revealed similar amounts of sialic acid in all portions of the kidney, but three times more in the glomeruli, which provided evidence that these stains depend on the presence of sIALic acid.
TL;DR: It is concluded that the macromolecules containing amino sugars released with crude trypsin and EDTA are likely to be heavily contaminated with intracellular material.
Abstract: Monolayers of baby-hamster kidney cells were grown on glass in tissue culture and harvested with trypsin or EDTA in order to investigate the cell surface macromolecules removed by these cell-disaggregating agents. The release of nucleic acids from the cells during the harvesting procedure was monitored by labelling the cellular RNA with [5-(3)H]uridine and the cellular DNA with [2-(14)C]thymidine. Treatment of the cells with EDTA was found to cause an increase in the permeability of the plasma membrane with 7.6% of the cellular RNA, but less than 1% of the cellular DNA, being released. Moreover, 61% of the cells harvested with EDTA were permeable to Trypan Blue. With crude trypsin, lysis of the cell occurred with the release of similar amounts of RNA and DNA amounting to about 11% of the total cellular nucleic acid. In contrast, crystalline trypsin released only 1% of the cellular nucleic acids. Since virtually all the cells (99%) after harvesting in crystalline trypsin were impermeable to Trypan Blue, this method was suitable for obtaining cell surface macromolecules without contamination by intracellular damage. [1-(14)C]Glucosamine was incorporated by the cells only into bound hexosamines and sialic acids. [By monitoring the release of radioactivity in high-molecular-weight material in such experiments a measure of the release of macromolecules containing amino sugars was obtained.] Of the total macromolecules containing amino sugars in the cells 33%, 24% and 13% were released when the cells were harvested with crude trypsin, crystalline trypsin or EDTA respectively. Crystalline trypsin also released 39% of the total sialic acid of the cell, whereas less than 1% of the cellular sialic acid was present in the EDTA-treated fraction. It is concluded that the macromolecules containing amino sugars released with crude trypsin and EDTA are likely to be heavily contaminated with intracellular material. However, the macromolecules released by crystalline trypsin appear to come from the cell surface.
TL;DR: It appeared that the exogenous and endogenous systems may well be identical except that the endogenous acceptor was removed during purification of the enzyme.
Abstract: A glycoprotein :N-acetylglucosamine transferase utilizing endogenous acceptors and a fetuin: N-acetylglucosamine transferase utilizing a defined exogenous fetuin acceptor from which sialic acid, galactose and N-acetylglucosamine had been removed were characterized from guinea pig liver Both glycoprotein :N-acetylglucosamine systems used UDP-N-acetylglucosamine as substrate, required Mn++ and had optimum pH of 54 Both enzyme systems were solubilized by extraction of the liver with 01% Triton X-100 The fetuin :N-acetylglucosamine transferase was separated from endogenous acceptors and purified more than 24-fold on Sephadex G-200 The endogenous system had a Km of 06 μM and the exogenous fetuin :N-acetylglucosamine transferase had a Km of 38 μM with respect to N-[14C]acetylglucosamine The fetuin :N-acetylglucosamine transferase was highly specific; 11 glycoproteins and 20 mono- and disaccharides and amino acids were negative when tested for acceptor activity The fetuin :N-acetylglucosamine transferase did not transfer any other nucleotide diphosphate sugar onto the acceptor; even UDP-N-acetylgalactosamine was not transferred It appeared that the exogenous and endogenous systems may well be identical except that the endogenous acceptor was removed during purification of the enzyme
TL;DR: The incorporation of glucosamine-14C into TCA-insoluble material at various times after infection was determined, suggesting that the glycopeptide is synthesized both early and late during the infection cycle.
Journal Article•
TL;DR: Comparative studies on the effect of enzyme digestion of sialic acid on the cellular electrokinetic charge were performed on two types of rat ascites hepatoma, finding that sIALic acid was similarly removable by the enzyme treatment from the cell surface in both types.
Abstract: Summary Comparative studies on the effect of enzyme digestion of sialic acid on the cellular electrokinetic charge were performed on two types of rat ascites hepatoma. There was no detectable change in the electrokinetic charge in the enzyme-treated cells from island-forming lines, whereas the negative surface charge was remarkably reduced in the treated cells from the free-cell lines. This difference in the electrokinetic property as detected by the enzyme treatment was simply dependent upon the surface property of cells, island-forming or free-living, which was cytogenetically fixed. Electron microscopic observations and assay of released sialic acid revealed that sialic acid was similarly removable by the enzyme treatment from the cell surface in both types. These results are discussed in connection with the chemical nature of the cell surface in both cell types.
TL;DR: It is proposed that there are several new, undescribed neuraminic acids in the jelly coat of the eggs of the sea urchin, since the sialic acid yielded only 45% of the color in the reaction with thiobarbituric acid as compared with the direct Ehrlich assay and, moreover, no release of sIALic acid from the complex by neuraminidase treatment was obtained.
TL;DR: The results of pronase digestion and treatment with alkali suggested the presence of the sialic acid in the carbohydrate moiety, not in the alkali-labile peptide moiety of the keratan sulfate fraction, which indicates that the sIALic acid is attached to the non-reducing end of the carbohydrates moiety.
TL;DR: Sheep anterior lens capsule appears to be a complex polymer of a collagen-like glycoprotein in association with noncollagen- like glycoproteins that resembles other basement membranes.
TL;DR: By a combination of Sephadex gel filtration, CM-C and DEAE-C chromatography, 2 highly purified HCG fractions were obtained from a crude preparation which was extracted from the urine of normal pregnant women in the first trimester.
Abstract: By a combination of Sephadex gel filtration, CM-C and DEAE-C chromatography, 2 highly purified HCG fractions (dA: 18,000 IU/mg, dB: 20,000 IU/mg) were obtained from a crude preparation (2130 IU/mg) which was extracted from the urine of normal pregnant women in the first trimester. They were characterized by histological response of the ovary of hypophysectomized immature rats, bioassay (the Steelman-Pohley method and the OAAD method), amino acid analysis and determination of carbohydrate content, and their high homogeneity was proved by polyacrylamide gel electrophoresis, immunodiffusion and immunoelectrophoresis. The components confirmed were 17 amino acids, galactose, mannose, hexosamine and sialic acid. LH-like activity was dominant in fraction dA, and this fraction was richer in proline and valine than fraction dB and poorer in aspartic acid, glutamic acid, glycine, alanine, lysine and histidine. Fraction dB had dominant FSH-like activity in its biological character and was richer in acidic amino acid...
TL;DR: The glycoprotein:galactosyl transferase was localized in the smooth internal membranes following fractionation of the Ehrlich ascites tumor membranes on a sucrose gradient and it was found that 80% of the theoretical receptor sites (galactose removed) of the α1-glycoprotein receptor would react after prolonged incubation.
TL;DR: Results and data taken from the literature support the conclusions that transferrins are polymorphic among some cercopithecines and that they are probably inherited as the products of nondominant autosomal alleles.
Abstract: The transferrin phenotypes of 11 species of Cercopithecinae were determined by electrophoresis of plasma, followed by autoradiography. Sialic acid content of transferrins was determined by electrophoresis and autoradiography of enzymatically treated plasma. Transferrin polymorphisms were found in three species. The transferrins of Cercopithecus spp., except C.patas., contain two sialic acid residues per molecule; transferrin of C.patas contains four sialic acid residues. The transferrins of Cercocebus spp. and Macaca spp. contain two sialic acid residues. The transferrins of Papio spp., except P. sphinx, contain four sialic acid residues per molecule; the transferrins of P. sphinx contain two sialic acid residues. These results and data taken from the literature support the conclusions that transferrins are polymorphic among some cercopithecines and that they are probably inherited as the products of nondominant autosomal alleles.
TL;DR: The lipid bases from gangliosides of human origin were predominantly sphinganine, while those of beef origin were the more typical unsaturated bases.
TL;DR: Removal of neuraminic acid had no appreciahle effect on any of the antigens studied, except M and N.
Abstract: . The effect of neuraminidnse-treatment on various human blood group antigens was investigated, Removal of neuraminic acid had no appreciahle effect on any of the antigens studied, except M and N.