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Showing papers on "Sialic acid published in 1969"


Journal ArticleDOI
TL;DR: It is concluded that the major, alkali-labile oligosaccharide of sialoglycopeptides is a tetrasaccharides and that other components are degradation products thereof.

424 citations


Journal ArticleDOI
TL;DR: The results suggest that sialic acid constituents of the lymphocyte surface play a critical role in ensuring the normal distribution of these cells in the body and imply that reactions involving surface sIALic acid can markedly alter the fate of lymphocytes without "killing" the cells.
Abstract: Evidence has been obtained that incubation of rat lymphocytes with neuraminidase, prior to intravenous transfusion into allogeneic or syngeneic recipients, alters the distribution of the cells. Many enzyme-treated lymphocytes initially become trapped in the liver, and there is a decrease in the selective accumulation of these cells in the lymph nodes and spleen. Subsequently, many enzyme-altered cells emigrate from the liver, concentrate in lymph nodes, and recirculate to the lymph. The results suggest that sialic acid constituents of the lymphocyte surface play a critical role in ensuring the normal distribution of these cells in the body. The findings also imply that reactions involving surface sialic acid can markedly alter the fate of lymphocytes without "killing" the cells.

269 citations


Journal ArticleDOI
TL;DR: The configuration of the ketosidic bond of sialic acid in naturally occurring substances, such as gangliosides, glycoproteins, and the like, is therefore the less stable anomer I, with the keto-d configuration equatorial and the carboxyl group axial to the pyranoid ring.

139 citations


Journal ArticleDOI
Om P. Bahl1
TL;DR: The carbohydrate chains in the hormone, as shown by this investigation, have the following monosaccharide sequence: N-acetylneuraminic acid, sialic acid or fucose being at the nonreducing ends of the chains.

124 citations



Journal ArticleDOI
TL;DR: While the composition of these lens capsules place them in the collagen group of proteins, they appear most closely related to other extracellular membranes, such as the renal glomerular basement membrane.

75 citations


Journal Article
TL;DR: The analytic and quantitative findings indicate that the HL-A alloantigen-carrying molecules have a similar fundamental structure.
Abstract: Human lymphocyte (HL-A) alloantigens have been isolated from human spleen and tissue culture cell sources Solubilization was accomplished by digesting membrane extracts with papain About 20% of all the alloantigens detected on the cell membrane were recovered in soluble form Purification of these materials was achieved by Sephadex chromatography and acrylamide gel electrophoresis The final purified fraction contained similar levels of several alloantigen specificities These materials lost alloantigenic activity at low pH, low NaCl concentration, and high temperatures Comparison of the amino acid composition of alloantigen preparations from two cell sources with different HL-A specificities revealed a general similarity in amino acid content These proteins contained sialic acid and neutral sugars, but amino sugars were absent The analytic and quantitative findings indicate that the HL-A alloantigen-carrying molecules have a similar fundamental structure

73 citations


Journal ArticleDOI
TL;DR: Quantitative analyses were made of carbohydrates and amino acids in Collocalia mucoid, finding that the most abundant amino acids are serine, threonine, aspartic acid, glutamic acid, proline, and valine.

69 citations


Journal ArticleDOI
TL;DR: Evidence is presented that the purified preparation of human chorionic gonadotropin is homogeneous in size and amino acid composition, but heterogeneous in electrical charge and sialic acid content.
Abstract: A purified preparation of human chorionic gonadotropin has been obtained by techniques of alcohol precipitation, ion exchange chromatography and gel filtration. Evidence is presented that the product is homogeneous in size and amino acid composition, but heterogeneous in electrical charge and sialic acid content. The polypeptide portion of the molecule has a high proline content (12.6 moles/mole of HCG) and appears to be composed of 2 identical subunits, each with a molecular weight in the range of 25,000 to 28,000. The biological activity of the purified material is in the range of 13,700 to 18,600 IU/mg. (Endocrinology 84: 298, 1969)

58 citations


Journal ArticleDOI
TL;DR: Protein-polysaccharides of chondroitin sulphate were extracted from fresh laryngeal cartilage at pH6.8 by two procedures and both preparations were heterogeneous in the ultracentrifuge, showing at least three components.
Abstract: 1. Protein–polysaccharides of chondroitin sulphate were extracted from fresh laryngeal cartilage at pH6·8 by two procedures. Procedure I consisted of brief low-speed homogenization in 0·15m (iso-osmotic) sodium acetate and procedure II consisted of longer homogenization followed by prolonged extraction in 10% calcium chloride solution. 2. The protein–polysaccharides in both extracts were isolated and purified by precipitation with 9-aminoacridine hydrochloride. They were free from serum proteins, collagen and nucleic acids and also of degradative enzymes. The absence of such enzymes was shown by viscosity measurements on solutions of protein–polysaccharides incubated for up to 24hr. at pH4 and 6·8. 3. Mannose, glucose or fucose were not detected by paper chromatography and only traces of sialic acid were present. 4. The yield with procedure II was twice that with procedure I and the products differed in their protein and glucosamine contents. 5. Hyaluronic acid was unlikely to have been precipitated at an acid pH, so the glucosamine was attributed to keratan sulphate, as serum proteins were absent. There was no free keratan sulphate in the preparation. 6. Both preparations were heterogeneous in the ultracentrifuge, showing at least three components.

52 citations


Journal ArticleDOI
TL;DR: A great loss of phospholipid content and a significant loss of sialic acid occur in the membrane of red cells from blood of male donors after storage of 42 days under blood banking conditions.

Journal ArticleDOI
TL;DR: The sialic acid-free M and N substances and glycopeptides from their pronase digest were treated with alkaline borohydride and products of degradation were fractionated, and the conclusion has been drawn that a part of carbohydrate moiety of M andN substances represents trisaccharides: N-acetylneuraminyl–galactosyl–N-acetygalactOSamine, linked to serine and threonine residues in the peptide
Abstract: The sialic acid-free M and N substances and glycopeptides from their pronase digest were treated with alkaline borohydride and products of degradation were fractionated. Galactose and N-acetylgalactosamine were split off during the degradation in the form of disaccharide: galactosyl-N-acetylgalactosaminitol, and it was accompanied by the release of amino acid components. The conclusion has been drawn that a part of carbohydrate moiety of M and N substances represents trisaccharides: N-acetylneuraminyl–galactosyl–N-acetylgalactosamine, linked to serine and threonine residues in the peptide chain by an alkali-labile O-glycosidic bond. The other type of oligosaccharides present in M and N substances is linked to peptide chain by an alkali-stabile bond and includes mannose, fucose, N-acetylglucosamine, the rest of sialic acid and galactose. The degraded M′ and N′ glycoproteins (M and N glycoproteins free of N-acetylneuraminic acid) did not inhibit the hemagglutination by Vicia graminea phytoagglutinins. The degraded native M and N substances were inactive towards both anti-M and anti-N rabbit immune sera, and anti-N phytoagglutinins from V. graminea, but they were still as good inhibitors of viral hemagglutination as untreated substances.

Journal ArticleDOI
TL;DR: The content and concentration of sialic acid in the testis, caput epididy-midis, cauda epididymidis and ductus deferens show changes during the transition from the prepuberal to the puberal state in the rat and the significance of these changes is discussed in relation to the maturation of spermatozoa.
Abstract: The content and concentration of sialic acid in the testis, caput epididy-midis, cauda epididymidis and ductus deferens show changes during the transition from the prepuberal to the puberal (mature) state in the rat The peak of sialic acid is attained in the caput epididymidis and cauda epididy-midis and ductus deferens between days 40 and 45 prior to the entry of sperms into these regions Following the entry of sperms there is a sharp decline in sialic acid till day 60 in the caput epididy-midis and ductus deferens while in the cauda epididy-midis the decline in sialic acid is only transient between days 45 and 50 and is followed by sharp increase at day 60 Efferent duct ligation caused a marked decrease in content of sialic acid in the caput epididy-midis only The significance of these changes is discussed in relation to the maturation of spermatozoa

Journal ArticleDOI
TL;DR: Periodate oxidation studies suggested that the two sialic acid residues are linked to galactose and N-acetylgalactosaminol, respectively, and a tentative structure is proposed.

Journal ArticleDOI
TL;DR: Twenty-four different glycoproteins were investigated for their ability to inhibit hemagglutination by the A/PRS and the B/Md influenza virus strains and the most potent inhibitors were the antigens of the human blood-group MN system and the Tamm-Horsfall urinary glycoprotein.
Abstract: Twenty-four different glycoproteins were investigated for their ability to inhibit hemagglutination by the A/PRS and the B/Md influenza virus strains. A relationship between activity, the molecular size, and sialic acid content was found. This relationship was readily shown for the A/PR8 virus if the properties of the glycoproteins were compared with one another on a per cent basis. A proportion of approximately 1:1:1 for activity (weight basis) to moles sialic acid content to molecular weight existed for each inhibitory glycoprotein with more than 3 per cent sialic acid, on comparison with any other active glycoprotein. A 1:3 correspondence between viral subunit and sialic acid residues of the inhibitor ovine submaxillary mucin was found experimentally and confirmed by calculation on a molecular model. The most potent inhibitors, were the antigens of the human blood-group MN system and the Tamm-Horsfall urinary glycoprotein.

Journal Article
TL;DR: A procedure for the isolation of a sialoglycopeptide fraction from the surface of Novikoff ascites cells has been developed and revealed the presence of the following monosaccharides: threonine, aspartic acid, glutamic acid, serine, proline, alanine, and valine.
Abstract: Summary Sialic acid has been shown to contribute significantly to the cell-surface charge of tumor cells. In order to elucidate the chemical nature of the sialic acid-containing molecules present on the tumor cell surface, a procedure for the isolation of a sialoglycopeptide fraction from the surface of Novikoff ascites cells has been developed. Digestion of tumor cell suspensions with papain liberates a sialoglycopeptide fraction from the cell surface. This fraction was partially purified using trichloroacetic acid precipitation, dialysis, and gel filtration on Sephadex G-50. The sialoglycopeptide fraction contains 65–80% of the neuraminidase-labile sialic acid present on the surface of these cells. Quantitative analysis of the composition of this fraction revealed the presence of the following monosaccharides, expressed per mg glycopeptide: 0.39 µmole sialic acid, 0.41 µmole glucosamine, 0.23 µmole galactosamine, 0.15 µmole mannose, 0.54 µmole galactose, 0.53 µmole glucose, and 0.15 µmole uronic acid. Amino acid analysis indicated a peptide content of 15%. Amino acids present in the highest amounts were threonine, aspartic acid, glutamic acid, serine, proline, alanine, and valine (molar ratio, 4:2:1.5:1:1:1:1).

Journal ArticleDOI
TL;DR: Porcine submaxillary mucin as prepared by the method developed in this laboratory showed strong blood group A activity, but much of this property was lost by treatment with dilute acids.

Journal ArticleDOI
TL;DR: A group of enzymes prepared from the culture fluids of streptococci belonging to groups A, B, C, G, and L, and from a strain of Streptococcus sanguis released a substance shown to belong to the sialic acid group from the specific substrate BSM-St, a sialomucoid prepared from bovine submaxillary gland.
Abstract: A group of enzymes were prepared from the culture fluids of streptococci belonging to groups A, B, C, G, and L, and from a strain of Streptococcus sanguis. These streptococcal enzymes (designated St-sialidases) released a substance shown to belong to the sialic acid group from the specific substrate BSM-St, a sialomucoid prepared from bovine submaxillary gland. They were inactive on N-acetylneuramin lactose prepared from bovine colustrum and on a sialomucoid prepared from bovine submaxillary mucin, whereas these substances are susceptible to sialidases produced by group K streptococci and by Vibrio cholerae. Some of the St-sialidases were markedly activated by divalent cations, but others showed little response. The heat stability of the enzymes produced by the different strains varied. The optimal pH was between 5.5 and 6.5 with acetate buffer and was about 7 with phosphate buffer. K(m) values were determined for the St-sialidases with BSM-St as substrate.

Journal ArticleDOI
TL;DR: Inhibitors of hemagglutination by type A2 influenza virus and a recently isolated strain of type B influenza virus were separated by sucrose density gradient centrifugation and agarose gel filtration from horse serum to define the important sialic acid prosthetic groups active in inhibition.
Abstract: Inhibitors of hemagglutination by type A2 influenza virus and a recently isolated strain of type B influenza virus were separated by sucrose density gradient centrifugation and agarose gel filtration from horse serum. Using selected reagents, it was demonstrated that the active substituent on the horse serum inhibitor of A2 influenza virus was 4-O-acetyl-N-acetylneuraminic acid; however, the active substituent on the inhibitor of the influenza B virus was shown to be N-acetylneuraminic acid (NANA). Sodium metaperiodate treatment of a component of horse serum resulted in a 10 to 15-fold enhancement of inhibitory activity against the type B virus, whereas the A2 inhibitor was completely destroyed. Since this enhancement did not occur with influenza B viruses isolated prior to 1965, it was considered that this sensitivity to an oxidized NANA glycoside may have been a reflection of an antigenic change which occurred at that time. The use of different virus strains and selected chemical reagents to define the important sialic acid prosthetic groups active in inhibition was described.

Journal ArticleDOI
01 Nov 1969-Lipids
TL;DR: A comparison is made of the sialic acid and hexose content of crude gangliosides from the brains of 13 species, including mammals, a bird, and amphibian, a reptile and fish, to find Ganglioside molecules are less abundant in tissues other than the brain.
Abstract: A comparison is made of the sialic acid and hexose content of crude gangliosides from the brains of 13 species, including mammals, a bird, and amphibian, a reptile and fish. The sialic acid content is relatively constant from species to species. Gangliosides are less abundant in tissues other than the brain. Four species (cat, dog, pig and sheep) were selected for the determination of their major ganglioside subfractions. The ganglioside subfractions were isolated (after extraction and partition dialysis) using descending thin layer chromatography. The population of ganglioside molecules varied from species to species. From dog and sheep a mono-, a di- and a trisialoganglioside were obtained; from cat a mono-, a di- and two trisialogangliosides; and from pig a mono- and two disialogangliosides. Each ganglioside subfraction was found to contain glucose, galactose and galactosamine in the ratio of approximately 1∶2∶1. The fatty acid moieties consisted of more than 80% stearic acid with lesser amounts of arachidic, palmitic and behenic acid. Sphingosine analyses indicated ratios of sphingosine to icosisphingosine of 7∶3 for the monosialo-, 1∶1 for the disialo- and 3∶7 for the trisialogangliosides.

Journal ArticleDOI
TL;DR: Sequential Smith degradation indicates that N-acetylgalactosamine residues may be present as points of branching in the inner part of the structure, adjacent to the carbohydrate-peptide bond(s); and Mannose residues appear to be linked in the 1,3-positions.
Abstract: 1. Bovine bone sialoprotein (mol.wt. 23000) contains N-acetylneuraminic acid and N-glycollylneuraminic acid, fucose, galactose, mannose, N-acetylgalactosamine and N-acetylglucosamine residues in the form of a very small number, perhaps one, of highly branched oligosaccharide structures linked covalently to peptide. 2. Periodate oxidation of the sialoprotein results in quantitative destruction only of the sialic acid and fucose residue consistent with the earlier findings of their positions as terminal groups. 3. Terminal sialic acid residues are attached to galactopyranose residues by 2,3-linkages, and to some N-acetylgalactosamine residues (at C-6). 4. Sequential Smith degradation indicates that N-acetylgalactosamine residues may be present as points of branching (linked in C-1, C-3 and C-6) and N-acetylglucosamine residues are located in the inner part of the structure, adjacent to the carbohydrate–peptide bond(s). 5. Mannose residues appear to be linked in the 1,3-positions.

Journal ArticleDOI
TL;DR: The results are consistent with the suggestion that carbohydrate incorporation into the membrane proteins studied occurs at many sites rather than at a particular site.

Journal ArticleDOI
TL;DR: The results do not enable us to determine whether ion‐binding to anionic sites at the electro‐kinetic surface is not an essential prerequisite to transmembrane movement, or whether it is essential, but occurs through the 40% of cell surface net negativity which is unaffected by ribonuclease‐ and neuraminidase‐treatment.
Abstract: The net negativity of the surfaces of Ehrlich ascites cells was reduced by treating them with either neuraminidase or ribonuclease. Neither enzyme treatment affected the Na+ or K+ content of the cells, before or after cooling at 4°C. Experiments with K42 revealed a reduction (9.5 to 17%) in unidirectional K+-fluxes following incubation with neuraminidase, but no change after ribonuclease-treatment. Our data suggest that surface anionic sites associated with RNA and sialic acid moieties are not of major quantitative importance in regulating either intracellular Na+ and K+ concentrations, or unidirectional transmembrane K+-flux. Our results do not enable us to determine whether ion-binding to anionic sites at the electro-kinetic surface is not an essential prerequisite to transmembrane movement, or whether it is essential, but occurs through the 40% of cell surface net negativity which is unaffected by ribonuclease- and neuraminidase-treatment.

Journal ArticleDOI
TL;DR: The results of the alkali treatment suggested that the linkages were through the hydroxyl group of threonine and serine to carbohydrates, and all the purified fractions showed dextrorotation.

Journal ArticleDOI
TL;DR: The electrophoretic characteristics of the murine CL3 ascites tumour were investigated, revealing that the surface proteins lack the basic amino acids lysine and arginine and a suggestion for the possible role of sialic acid at the cell surface is mentioned.
Abstract: The electrophoretic characteristics of the murine CL3 ascites tumour were investigated. Treatment of the cells with formaldehyde raised the electrophoretic mobility (E.P.M.) from - 1.06 to - 1.28 µ/sec/V/cm; subsequent treatment with diazomethane reduced their mobility to zero. The E.P.M. of the diazomethane-treated cells did not alter over the pH range 3.0-8.0. This proved that the only ionic groups at this cell surface were amino and carboxyl groups. The absence of phosphate groups, another possibility, was confirmed by the lack of calcium-ion binding from 10 mM Ca 2+ solutions. Neuraminidase treatment reduced the E.P.M. from -1.06 to -0.55 µ/sec/V/cm and free sialic acid was identified in the enzyme supernatant. Subsequent treatment of the cells with formaldehyde raised the mobility to -1.22 µ/sec/V/cm indicating that the change in E.P.M. on neuraminidase treatment was not due solely to the removal of the carboxyl groups of sialic acid but also to a change in the ionic nature of the surface. This change is ascribed to a change in the conformation of the surface protein. The reason for this change and a suggestion for the possible role of sialic acid at the cell surface are mentioned. Treatment of the cells with trypsin did not affect the viable cells in any way, suggesting that the surface proteins lack the basic amino acids lysine and arginine. Pronase treatment served only to show that much of the sialic acid was bound to protein; the total amount was not determined.

Journal ArticleDOI
TL;DR: It is suggested that the sialic acid residue of the external cell surface may have a significant role in amino-acid transport in human cells.
Abstract: SummaryAn amino acid transport system in HeLa cells utilizing 14C-l-alpha-aminoisobutyric acid is described. Neuraminidase treatment of HeLa cells decreases the net accumulation of amino acid without alteration of the rate of efflux of preloaded cells. These studies suggest that the sialic acid residue of the external cell surface may have a significant role in amino-acid transport in human cells.

Journal ArticleDOI
TL;DR: The immunochemical method appears to be a useful one for elucidating structural differences in ganglioside molecules and both the sequence of carbohydrate residues and position of NANA residues played a critical role in the formation of precipitation bands with NHG‐antisera.
Abstract: — Gangliosides G1 to G5 were isolated from human brain by means of TLC and tested with respect to their specificity to antisera against normal brain and Tay-Sachs brain gangliosides by agar double diffusion analysis. Gangliosides G2 and G4 gave precipitation reactions with antisera to normal human gangliosides (NHG) while only ganglioside G6 reacted with antisera to Tay-Sachs gangliosides (TSG). Additional specificity information was also obtained by use of the enzyme neuraminidase for the removal of specific sialic acid (NANA) residues. It was concluded from these data that the specificity of the anti-NHG antibodies is determined by the presence of a galactose (β1, 3) N-acetyl galactos-amine–while that of anti-TSG antibodies is due to a N-acetyl galactosamine (β1, 4) galactose-end sequence. By means of natural compounds of known structure it was found that both the sequence of carbohydrate residues and position of NANA residues in the molecule played a critical role in the formation of precipitation bands with NHG-antisera. This information was utilized to distinguish one isomeric form of disialoganglioside from another, i.e. G2 from G3 and to confirm the structure of the trisialoganglioside, G1. The immunochemical method appears to be a useful one for elucidating structural differences in ganglioside molecules.

Journal ArticleDOI
TL;DR: Studies on the subcellular distribution of enzymatic activity in the retina showed that the “nuclear fraction” prepared from 0·25 m sucrose homogenates of the tissue contained most of the activity, and some implications of the nuclear location of sialic acid activation are discussed.

Journal ArticleDOI
TL;DR: The new lipid is a ganglioside sulfate, which is called "ungulic acid" because it was first separated and identified from a horse's hoof (Latin, ungula).

Journal ArticleDOI
TL;DR: A subunit of the bovine erythrocyte membrane which resulted from ether and alkali extraction of stroma was found to retain possibly all of the blood group factors of the intact red blood cells.
Abstract: Summary. A subunit of the bovine erythrocyte membrane which resulted from ether and alkali extraction of stroma was found to retain possibly all of the blood group factors of the intact red blood cells. Factors in the A, B, C, F, L, S and Z systems were detected. Papain degradation of this elinin preparation resulted in loss of all detectable factors except F, V and C when they were present in the source material. The F and V properties were clearly separated from each other. The F property remained with the insoluble residue while the V was found in soluble form in the reaction supernatant. The V factor could also be released from stroma by similar papain treatment. The F factor was destroyed by treatment with neuraminidase while no other factor was found to be affected. There was evidence that more sialic acid could be released by neuraminidase or by acid hydrolysis from F-positive than from F-negative erythrocyte stroma.