Showing papers on "Sialic acid published in 1977"
TL;DR: Preliminary experiments suggest that even the "low uptake" form of α-l-iduronidase may be taken up by receptor binding, although with much lower affinity.
331 citations
TL;DR: The surface of Neonatal rat cells in culture, neonatal rat hearts, and adult rabbit hearts have qualitatively similar responses to lanthanum, ruthenium red, and colloidal iron stains, indicating that the integrity of surface coat is critical in the regulation of Ca (and La) exchange but that K* permeability is controlled at the bilayer region.
Abstract: The surface of neonatal rat cells in culture, neonatal rat hearts, and adult rabbit hearts have qualitatively similar responses to lanthanum, ruthenium red, and colloidal iron stains. All demonstrate a surface coat and external lamina with abundant negatively charged sites. Cells with intact surface structure do not permit entry of lanthanum (La) intracellularly. The surface of all the myocardial cells studied contained abundant sialic acid distributed in two distinct layers, one in the surface coat next to the lipid bilayer, the other in the external lamina at the interstitial interface. The removal of sialic acid from the cellular surface increases calcium (Ca) exchangeability 5to 6-fold. Its removal also permits La to enter the cell and displace more than 80% of cellular Ca. Despite these marked alterations in Ca and La permeability, sialic acid removal has no effect on potassium
229 citations
TL;DR: Data suggest that the variant cells of Chinese hamster ovary cells fail to carry out specific glycosyltransferase reactions in vivo despite the fact that they possess the appropriate nucleotide sugars, glycoprotein and glycolipid acceptors, and glycosYLtransferases.
216 citations
TL;DR: The chemical and physical properties of the avian protein have been evaluated with respect to the analogous hepatic protein, of mammalian origin, which exhibits a binding specificity for galactose-terminal serum glycoproteins.
184 citations
TL;DR: It is demonstrated that desialylation of Factor VIII/van Willebrand factor does not affect procoagulant activity, decreases ristocetin-induced platelet-aggregating activity, and as observed with other plasma glycoproteins, facilitates its rapid hepatic clearance.
179 citations
170 citations
TL;DR: Kinetic properties of the enzyme in the presence and absence of inhibitors suggest that the sialylated product has an equilibrium random order mechanism.
168 citations
TL;DR: The genetic basis for the distinctive capacity of influenza A/WSN/33 (H0N1) virus (WSN virus) to produce plaques on bovine kidney (MDBK) cells was found to be related to virus neuraminidase, which is in accord with the hypothesis that neuraminidsase may facilitate production of infectious particles by removing sialic acid residues and exposing appropriate cleavage sites on hemagglutinin.
Abstract: The genetic basis for the distinctive capacity of influenza A/WSN/33 (H0N1) virus (WSN virus) to produce plaques on bovine kidney (MDBK) cells was found to be related to virus neuraminidase. Recombinant viruses that derived only the neuraminidase of WSN virus were capable of producing plaques, whereas recombinant viruses identical to WSN except for neuraminidase did not produce plaques. With viruses that do not contain WSN neuraminidase, infectivity of virus yields from MDBK cells was increased approximately 1,000-fold after in vitro treatment with trypsin. In contrast, no significant increase in infectivity was observed after trypsin treatment of viruses containing WSN neuraminidase. In addition, polyacrylamide gel analysis of proteins of WSN virus obtained after infection of MDBK cells demonstrated that hemagglutinin was present in the cleaved form (HA1 + HA2), whereas only uncleaved hemagglutinin was obtained with a recombinant virus that derived all of its genes from WSN virus except its neuraminidase. These data are in accord with the hypothesis that neuraminidase may facilitate production of infectious particles by removing sialic acid residues and exposing appropriate cleavage sites on hemagglutinin.
147 citations
TL;DR: The purified neuraminidase was shown to be free from protease, N-acetylneuraminic acid aldolase, phospholipase C, and glycosidases, and the modified procedure gave a higher molecular extinction coefficient.
Abstract: Neuraminidase [sialidase, EC 3.2.1.18] was found to be widely distributed in bacteria belonging to Arthrobacter. Among these bacteria, Arthrobacter ureafaciens, A. oxydans, and A. aurescens produced relatively potent neuraminidase activities. For the production of this enzyme, not only colominic acid, a homopolymer of N-acetylneuraminic acid, but also N-acetylneuraminic acid, the reaction product of this enzyme, are effective as sources of carbon. An affinity adsorbent specific for neuraminidase was prepared by cross-linking colominic acid with soluble starch by means of epichlorohydrin. Neuraminidase from A. ureafaciens could be purified on this affinity column. The purified neuraminidase was shown to be free from protease, N-acetylneuraminic acid aldolase, phospholipase C, and glycosidases. Aminoff's assay procedure for sialic acid was modified to avoid the centrifugation step. The modified procedure gave a higher molecular extinction coefficient.
145 citations
TL;DR: It is hypothesized that the basic metabolic lesion in mucolipidosis I lies in a defective degradation of sialic acid-containing compounds due to the genetic deficiency of a neuraminidase.
142 citations
TL;DR: The data indicate that spontaneously metastasizing mammary tumor cells have an increased production and release, perhaps through cell surface shedding, of a sialyltransferase, which may increase the serum half-life of certain tumor-specific circulating glycoconjugates by increasing the content of protein-bound sialic acid and may thereby play a role in the immune escape mechanism of metastasized tumor cells.
Abstract: Rats with transplantable spontaneously metastasizing mammary tumors have elevated levels of both serum sialoglycoconjugate and serum sialytransferase activity compared with normal female rats or rats with various nonmetastasizing mammary tumors. A direct relationship was observed between the amount of serum protein-bound sialic acid and serum sialyltransferase activity in all rats studied. Serum sialyltransferase activity in rats with a representative metastasizing mammary tumor, SMT-2A, was also correlated with tumor age. Microsomes prepared from the SMT-2A tumor have a sixfold higher sialyltransferase activity than do microsomes prepared from the nonmetastasizing mammary tumor MT-W9B. Normal rat liver microsomes have the same level of activity as microsomes prepared from livers of animals with either SMT-2A or MT-W9B tumors. The data indicate that spontaneously metastasizing mammary tumor cells have an increased production and release, perhaps through cell surface shedding, of a sialyltransferase. It is suggested that this sialyltransferase may increase the serum half-life of certain tumor-specific circulating glycoconjugates by increasing the content of protein-bound sialic acid and may thereby play a role in the immune escape mechanism of metastasizing tumor cells.
TL;DR: The results obtained indicate a preferential recognition of sialidase-treated as compared to normal erythrocytes by mono-nuclear spleen cells and Kupffer cells of the liver, which could explain the removal of enzyme-treated ery Throttlecytes from the circulation with their accumulation in liver and spleen.
Abstract: Sialidase (neuraminidase; acylneuraminyl hydrolase; EC 3.2.1.18)-treated erythrocytes obtained from different species are susceptible to rapid elimination from the circulation and are sequestered in the liver and spleen. The present studies were concerned with the mechanism of this clearance and how it may relate to the normal physiological process of removing senescent erythrocytes from the circulation. The results obtained indicate a preferential recognition of sialidase-treated as compared to normal erythrocytes by mono-nuclear spleen cells and Kupffer cells of the liver. This recognition manifests itself in both autologous and homologous systems by adhesion of the complementary cells in the form of rosettes, and as such could explain the removal of enzyme-treated erythrocytes from the circulation with their accumulation in liver and spleen. This phenomenon may represent a normal physiological mechanism for removal of senescent erythrocytes containing decreased sialic acid.
TL;DR: In mice bearing transplantable mammary carcinomas, serum levels of sialic acid-containing glycolipids were elevated 2.5-fold in pooled serum samples from which gangliosides were purified by column chromatography and appeared in advance of palpable tumors.
Abstract: In mice bearing transplantable mammary carcinomas, serum levels of sialic acid-containing glycolipids were elevated 2.5-fold in pooled serum samples from which gangliosides were purified by column chromatography. A method is also described by which ganglioside content was estimated on as little as 1.0 ml of whole blood to permit studies with individual tumor-bearing mice and age- and litter-matched controls. Using this method, we observed similar elevations in ganglioside levels that were independent of age and sex of the animal and appeared in advance of palpable tumors. Following excision of the tumors, the glycolipid sialic acid values dropped below control levels and remained there. Serum sialic acid of the glycolipid fraction was elevated nearly 2-fold in human carcinoma patients and appeared to decline after surgery.
TL;DR: The data indicate that the two major oligosaccharide moieties of the glycoprotein have similar structures, each having two or three branches terminating in the sequence sialic acid-galactose- N -acetylglucosamine at the nonreducing end of the oligose chain.
TL;DR: The ability of saliva to induce aggregation of Streptococcus sanguis was destroyed by treating the saliva with protease or neuraminidase, and aggregating activity was not related to the rhamnose or phosphorous content of the cell wall or to antigen a, b, c, d, or e.
Abstract: The ability of saliva to induce aggregation of Streptococcus sanguis was destroyed by treating the saliva with protease or neuraminidase. Loss of aggregating activity could be correlated with the appearance of free sialic acid. Clarified saliva contains an endogenous neuraminidase that modifies aggregating activity. Aggregation was inhibited by mixed ganglioside preparations but less effectively by acid-hydrolyzed gangliosides. The aggregating activity of S. sanguis was not related to the rhamnose or phosphorous content of the cell wall or to antigen a, b, c, d, or e.
TL;DR: Comparison of natural abundance 13C NMR spectra of the Bos-12polysaccharide with group B and C meningococcal polysaccharides established that Bos- 12 was either an equimolar mixture of 2 leads to 8-alpha linked sialic acid homopolymers or (b) a 2 leading to 8alpha/2 leads to 9-alpha heteropolymer.
Abstract: A polysaccharide, antigenically related to group C meningococcus, has been isolated from Escherichia coli strain Bos-12 (016; K92; NM). Like groups B and C meningococcal polysaccharide, the Bos-12 antigen is a pure polymer of sialic acid. 13C NMR studies on the meningococcal group B and C polysaccharides have indicated that the former consists of sialic acid units linked 2 leads to 8- alpha, whereas the latter contains the sialic acid residues linked 2 leads to 9-alpha (Bhattacharjee, A.K., Jennings, H.J., Kenny, C.P., Martin, A., and Smith, I.C.P. (1975), J. Biol. Chem. 250, 1926). Comparison of natural abundance 13C NMR spectra of the Bos-12 polysaccharide with group B and C meningococcal polysaccharides established that Bos-12 was either (a) an equimolar mixture of 2 leads to 8-alpha linked sialic acid homopolymers or (b) a 2 leads to 8-alpha/2 leads to 9-alpha heteropolymer. These possibilities were distinguished in the following manner. The fact that Bos-12 polysaccharide precipitated with anti-group C serum but not with anti-group B serum would seem to exclude a. Further, chemical studies (periodate oxidation followed by tritiated NaBH4 reduction) gave saccharides with a radioactive-labeling pattern expected for alternating 2 leads to 8-alpha/2 leads to 9-alpha sialic acid linkages. Bos-12 is thus an 2 leads to 8/2 lead to 9-alpha heteropolymer.
TL;DR: In this article, the relationship between cell surface sialic acid and cell surface-charge density for the extreme density fractions of fresh human red cells was examined and no differences in net surface charge density were observed.
TL;DR: The gamma-glutamyl analogs, 6-diazo-5-oxo-L-norleucine (DON) and L-azaserine inactivate the human kidney enzyme with respect to its transpeptidase and hydrolase activities and is accelerated by maleate.
TL;DR: PP5 was found to inhibit the activity of trypsin and plasmin; the biological role of this protein therefore may be the inhibition of proteases.
Abstract: The isolation and characterization of placemental protein PP5 is described. The purification was achieved by use of immunoadsorbents. From the tissue of one human term placenta an average amount of 15 mg PP5 can be extracted. PP5 apparently is specific for the placenta; it could not be detected in extracts from other human tissues. In sera from pregnant women PP5 is not present or only in trace amounts (less than 0.1 mg%). In the ultracentrifuge PP5 was found to have a sedimentation coefficient of 2.8 S and a molecular weight of 36,600 daltons. Electrophoretically the protein migrates as a fast beta1-globulin. The isoelectric point was determined to be 4.6. PP5 is a glycoprotein and contains 19.8% carbohydrates (hexoses 10.0%, hexosamine 4.4%, fucose 0.4%, sialic acid 5.0%). The amino acid composition of the protein is reported, too. PP5 was found to inhibit the activity of trypsin and plasmin; the biological role of this protein therefore may be the inhibition of proteases.
TL;DR: The phenotype suggests defective degradation primarily of glycoproteins and possibly to a lesser extent of keratan sulfate and gangliosides in an 8-month-old female with coarse facies and hepatosplenomegaly.
Abstract: An 8-month-old female presented with coarse facies and hepatosplenomegaly at birth. Growth proceeded at an accelerated rate and mental development was normal. A pattern of dysostosis multiplex developed radiographically. Cytoplasmic inclusions consistent with lysosomal storage disease were demonstrated by electron microscopy in bone marrow, liver, and cartilage cells and in cultured skin fibroblasts. Assays of the fibroblasts revealed a specific deficiency of acid neuraminidase and 6-fold increase in intracellular bound sialic acid. An unidentified macromolecular compound rich in sialic acid was excreted in excessive amounts in the urine. The phenotype suggests defective degradation primarily of glycoproteins and possibly to a lesser extent of keratan sulfate and gangliosides.
TL;DR: Removal of sialic acid from a specific hepatic binding protein virtually abolishes its capacity to bind certain asialoglycoproteins.
Abstract: Removal of sialic acid from a specific hepatic binding protein virtually abolishes its capacity to bind certain asialoglycoproteins. The loss of this capacity is the result of competition for the binding sites by galactosyl residues, of hepatic binding protein, that become terminal after desialylation.
TL;DR: The results suggest that serum protein‐bound carbohydrates or glycoproteins may be of adjunctive value in assessing tumor burden and immune reactivity in cancer patients.
Abstract: Levels of glycoprotein-associated carbohydrates (neutral hexoses, hexosamine, sialic acid and fucose) were determined in the serum of patients with either local, regional or metastatic cancer, patients clinically cured of cancer, and controls (smokers and nonsmokers). Total protein-bound carbohydrates were compared with levels of 17 normal serum glycoproteins, carcinoembryonic antigen (CEA), and with lymphocyte reactivity to phytohemagglutin (PHA). Tumor burden was directly related to protein-bound carbohydrate levels in patient groups. Levels of bound carbohydrates reflect the sum of all the changes in serum glycoproteins, but primarily changes in the acute-phase proteins (alpha 1-acid glycoprotein, alpha 1-antitrypsin, haptoglobin, ceruloplasmin) found in the alpha-globulin fraction of serum. Increases in protein-bound carbohydrates in tumor-bearers were not related to increases in CEA. Increased levels of the acute-phase proteins occurred in individuals with depressed in vitro lymphocyte reactivity to PHA. A significant positive correlation was found between lymphocyte reactivity and level of alpha 2HS-glycoprotein. The results suggest that serum protein-bound carbohydrates or glycoproteins may be of adjunctive value is assessing tumor burden and immune reactivity in cancer patients.
TL;DR: E. coli K92 strains may provide an alternative immunogen for prophylaxis against disease due to group C N. meningitidis in infants and young children.
Abstract: Antibodies to capsular polysaccharides of group C Neisseria meningitidis are often found in sera of young adults despite infrequent nasopharyngeal carriage and low rate of attack of N. meningitidis in the United States. Thus, experiments were designed for detection of bacteria cross-reactive with N. meningitidis. Among 3,264 cultures of stool, urine, blood, and cerebrospinal fluid, only 14 strains were found to be cross-reactive; all were Escherichia coli possessing the K92 capsular polysaccharide. The somatic O-antigens were 16, 13, 23, and 73; the flagellar antigens were H4 and 34. All K92 strains of E. coli showed the expected fermentations, were sensitive to common antibiotics, and lacked enteropathogenicity. Antigens of both E. coli K92 and group C N. meningitidis are capsular, acidic polysaccharides composed of sialic acid. The K92 polysaccharide is N- but not O-acetylated, sensitive to neuraminidase, and linked by alpha-2,8- alternating with alpha-2,9-ketosidic bonds. The K92 polysaccharides from all E. coli studied had similar biophysical and immunological properties. Intravenous injection of formalin-treated K92 organisms induced precipitating and bactericidal antibodies to polysaccharides of N. meningitidis. E. coli K92 strains may provide an alternative immunogen for prophylaxis against disease due to group C N. meningitidis in infants and young children.
TL;DR: The results indicate that the soluble and membrane-bound forms of dopamine β-hydroxylase have different synthesis rates, and are discussed in connection with the concept that membranes of chromaffin granules are reused for several secretory cycles.
01 Jan 1977
TL;DR: In this paper, experiments were designed for detection of bacteria cross-reactive with Neisseria meningitidis in sera of young adults despite infrequent nasopharyngeal carriage and low rate of attack of N. meningidis in the United States.
Abstract: Antibodies to capsular polysaccharides of group C Neisseria meningitidis are often found in sera of young adults despite infrequent nasopharyngeal carriage and low rate of attack of N. meningitidis in the United States. Thus, experiments were designed for detection of bacteria cross-reactive with N. meningitidis. Among 3,264 cultures of stool, urine, blood, and cerebrospinal fluid, only 14 strains were found to be cross-reactive; all were Escherichia coli possessing the K92 capsular polysaccharide. The somatic O-antigens were 16, 13, 23, and 73; the flagellar antigens were H4 and 34. All K92 strains of E. coli showed the expected fermentations, were sensitive to common antibiotics, and lacked enteropathogenicity. Antigens of both E. coli K92 and group C N. meningitidis are capsular, acidic polysaccharides composed of sialic acid. The K92 polysaccharide is N- but not O-acetylated, sensitive to neuraminidase, and linked by a-2,8- alternating with a-2,9-ketosidic bonds. The K92 polysaccharides from all E. coli studied had similar biophysical and immunological properties. Intravenous injection of formalin-treated K92 organisms induced precipitating and bactericidal antibodies to polysaccharides of N. meningitidis. E. coli K92 strains may provide an alternative immunogen for prophylaxis against disease due to group C N. meningitidis in infants and young children.
TL;DR: The results of this study indicate that both glycolipid- and glycoprotein-bound sialic acid in the synaptic membrane are releasable in situ by the action of the intrinsic synaptic membrane sialidase, and they suggest that this enzyme may act to modulate the physical properties of the membrane.
TL;DR: The newly synthesized GM3, the product of the reaction, was incorporated into or became tightlyassociated with the membranes of the Golgi apparatus, indicating that it is tightly associated with the membrane.
TL;DR: The alpha-L-fucosidase from rat liver lysosomes was purified approximately 27,000-fold (from cytoplasmic extract) by a rapid procedure requiring only 7 h anf providing enzyme in a 20 per cent yield, suggesting that the enzyme is a tetramer.
TL;DR: It is demonstrated that a defect in glycoprotein synthesis is the biochemical basis for the reduction in proteins exposed at the outer surface of the mutant cells, and that feeding the mutants 10 mM N-acetylglucosamine reverts them to the wild type phenotype.
Journal Article•
TL;DR: Asialofibrinogen clots faster due to enhancement of its monomer aggregation, has a normal capacity to form cross-linked fibrin, and does not differ significantly in its metabolic properties from normal fibr inogen.