Search PubMed⌕ Search

Biomedical subjects

A Kobata

Publications and source records attributed to A Kobata.

At least 217 records · Page 12Linked to original sources
PubMed1981

Studies on the structures of the carbohydrate moiety of human prothrombin.

Human prothrombin contains three asparagine-linked sugar chains in one molecule. The sugar chains were quantitatively liberated as radioactive oligosaccharides from the polypeptide moiety by hydrazinolysis followed by N-acetylation and Nab3H4 reduction. All of the oligosaccharides contain N-acetylneuraminic acid. The neutral oligosaccharides obtained from all acidic oligosaccharides by sialidase digestion are identical. By the combination of sequential exoglycosidase digestion and methylation analysis, the structures of the asparagine-linked sugar chains of human prothrombin were confirmed to be as follows: (sequence in text).

Carbohydrate Sequence↗
PubMed1981

Structural study of the sugar chains of alpha-amylases produced ectopically in tumors.

About thirty percent of two alpha-amylases produced from a serous papillary cystadenocarcinoma of the ovarium (case 1) and a bronchioloalveolar adenocarcinoma of the lung (case 2) was glycoproteins containing 1 mol of asparagine-linked sugar chain, respectively. The structures of the sugar moieties were found by sequential enzymatic degradation and methylation analysis to be as follows: [(Gal beta 1 leads to 4)0 or 1GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(3)][GlcNAc beta 1 leads to 2Man alpha 1 leads to 3(6)]Man beta 1 leads to 4GlcNAc beta 1 leads to 4(Fuc alpha 1 leads to 6)GlcNAc and [(Gal beta 1 leads to 4)0 or 1GlcNAc beta 1 leads to 2Man alpha 1 leads to 6][NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3]Man beta 1 leads to 4GlcNAc beta 1 leads to 4(Fuc alpha 1 leads to 6)GlcNAc. Structures of asparagine-linked sugar chains were the same in the tumors of cases 1 and 2 and were incomplete in comparison with those of the parotid amylase.

Adenocarcinoma↗
PubMed1981

Digestion of asparagine-linked oligosaccharides by endo-beta-N-acetylglucosaminidase in the human skin fibroblasts obtained from fucosidosis patients.

The substrate specificity of human endo-beta-N-acetylglucosaminidase was studied by using the homogenate of cultured skin fibroblasts of fucosidosis patients as an enzyme source. The results indicate that biantennary complex type asparagine-linked sugar chains as well as high mannose type sugar chains are cleaved by the enzyme action. None of the sugar chains with a fucosyl residue on the proximal N-acetylglucosamine of their N,N'-diacetylchitobiose moieties was cleaved. These results proved enzymatically the mechanism of production of oligosaccharides detected in the urine of various exoglycosidase deficiencies.

Acetylglucosaminidase↗
PubMed1980

The asparagine-linked sugar chains of the glycoproteins in calf thymocyte plasma membrane. Structural studies of acidic oligosaccharides.

The acidic oligosaccharide fraction obtained by paper electrophoresis of the hydrazinolysate of the plasma membrane glycoprotein mixture of calf thymocytes was fractionated by high voltage paper electrophoresis into 15 acidic components. Three of them were mixtures of two acidic oligosaccharides, while the remaining 12 were almost pure acidic oligosaccharides. The 18 oligosaccharides have a common core hexasaccharide, Man alpha 1 yields 6(man beta 1 yields 3)Man beta 1 yields 4GlcNAc beta 1 yields 4(Fuc alpha 1 yields 6)GlcNAc. The number of outer chains ranges from two to four. Three different types of outer chains, Gal beta 1 yields 4 GlcNAc beta 1 yields, Gal beta 1 yields 3 GlcNAc beta 1 yields, and Gal beta 1 yields 4 GlcNAc beta 1 yields 3Gal beta 1 yields 4GlcNAc beta 1 yields, were found to occur in the acidic oligosaccharides in various combination. In the biantennary oligosaccharides, the two outer chains are linked only at the C-2 position of the two alpha-mannosyl residues of the core hexasaccharide. All triantennary oligosaccharides have an additional outer chain at the C-4 position of the alpha-mannosyl residue constructing the Man alpha 1 yields 6Man group of the core. Two outer chains of tetraantennary oligosaccharides are linked at the C-2 and 4 positions of one alpha-mannosyl residue and the remaining two outer chains at the C-2 and 6 positions of the other alpha-mannosyl residue of the core. An interesting observation is that C-2,6 disubstitution always occurs on the alpha-mannosyl residue of the Man alpha 1 yields 6 side in all oligosaccharides with Gal beta 1 yields 4GlcNAc beta 1 yields 3Gal beta 1 yields 4GlcNAc beta 1 yields outer chain, while in other tetraantennary oligosaccharides, C-2,6 disubstitution always occurs on the alpha-mannosyl residue of the Man alpha 1 yields 3 side. No sialylated Gal beta 1 yields 3Gal beta 1 yields 4GlcNAc beta 1 yields outer chain was found in the acidic oligosaccharides studied in this paper.

Animals↗
PubMed1980

Structures of the asparagine-linked sugar chains of glycophorin A.

Glycophorin A isolated from human erythrocytes contains one asparagine-linked sugar chain in one molecule. This sugar chain was successfully released as an oligosaccharide fraction by hydrazinolysis. The oligosaccharide fraction was separated into four components (N, A-1, A-2', and A-2) by paper electrophoresis. Complete structures of the major acidic oligosaccharides (A-1 and A-2) were elucidated by sequential exoglycosidase digestion in combination with methylation study and periodate oxidation as follows: NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(3) [Gal beta 1 leads to 4GlcNAc beta 1 leads to to 2Man alpha 1 leads to 3(6)] (GlcNAc beta 1 leads to 4)Man beta 1 leads to 4GlcNAc beta 1 leads to 4(Fuc alpha 1 leads to 6)GlcNAc and NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3) (GlcNAc beta 1 leads to 4)Man beta 1 leads to 4GlcNAc beta 1 leads to 4(Fuc alpha 1 leads to 6) GlcNAc. The abbreviations used are: NeuAc, N-acetylneuraminic acid; GlcNAc, N-acetylglucosamine; Fuc, fucose.

Asparagine↗
PubMed1980

Structural studies of the sugar chains of human parotid alpha-amylase.

Human parotid amylase can be separated into three families of isoenzymes (A', A, and B) by Sephadex G-75 column chromatography. Isoenzymes in family B were free from carbohydrate, while those in family A were all glycoproteins. The carbohydrate moieties of family A isoenzymes were released from their polypeptide portions by hydrazinolysis and labeled by reduction with NaB[3H]4. The yield of total radioactive oligosaccharides indicated that family A isoenzymes all contain single asparagine-linked sugar chains in one molecule. The radioactive oligosaccharides were fractionated into one acidic and two neutral oligosaccharide fractions by paper electrophoresis and paper chromatography. By sequential exoglycosidase digestion in combination with a methylation study, their structures were determined to be: Gal beta 1 leads to 4 (Fuc alpha 1 leads to 3)GlcNAc beta 1 leads to 2Man alpha 1 leads to 6[Gal beta 1 leads to 4(Fuc alpha 1 leads to 3)GlcNAc beta 1 leads to 2Man alpha 1 leads to 3]Man beta 1 leads to 4GlcNAc beta 1 leads to 4(Fuc alpha 1 leads to 6)GlcNAc Gal beta 1 leads to 4(Fuc alpha 1 leads to 3)GlcNAc beta 1 leads to 2Man alpha 1 leads to 6 and 3[Gal beta 1 leads to 4 GlcNAc beta 1 leads to 2Man alpha 1 leads to 3 and 6]Man beta 1 leads to 4GlcNAc beta 1 leads to 4(Fuc alpha 1 leads to 6)GlcNAc Gal beta 1 leads to 4(Fuc alpha 1 leads to 3) GlcNAc beta 1 leads to 2Man alpha 1 leads to 6 (NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc beta 1 leads to 4(Fuc alpha 1 leads to 6)GlcNAc.

Amylases↗
PubMed1980

Urinary oligosaccharides of mannosidosis.

Nine oligosaccharide fractions were purified from the urine of mannosidosis patients by Bio-Gel P-4 column chromatography, paper chromatography, and paper electrophoresis. Studies using exoglycosidase digestion, methylation analysis, periodate oxidation, and acetolysis revealed that most of the fractions were mixtures of two or three isomeric oligosaccharides. The structures of a total of 16 oligosaccharides were elucidated to be as follows: (formula: see text).

Adolescent↗
PubMed1980

The structures of the carbohydrate moieties of bovine blood coagulation factor X.

Bovine blood coagulation factor X contains both asparagine-linked and threonine-linked oligosaccharides. The asparagine-linked chain is a mixture of a tridecasaccharide NeuAc alpha 2 leads to 3Gal beta 1 leads to 3(NeuAc alpha 2 leads to 6)GlcNAc beta 1 leads to 2Man alpha 1 leads to 6[NeuAc alpha 2 leads to 3Gal beta 1 leads to 3(NeuAc alpha 2 leads to 6)GlcNAc beta 1 leads to 2Man alpha 1 leads to 3]Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc and a dodecasaccharide NeuAc alpha 2 leads to 6 Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6[NeuAc alpha 2 leads to 3Gal beta 1 leads to 3(NeuAc alpha 2 leads to 6)GlcNAc beta 1 leads to 2Man alpha 1 leads to 3]Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc and their partial desialylation products. The threonine-linked chain is a mixture of NeuAc alpha 2 leads to 3Gal beta 1 leads to 3(NeuAc alpha 2 leads to 6)GalNAc, NeuAc alpha 2 leads to 3Gal beta 1 leads to 3(NeuGly alpha 2 leads to 6)GalNAc, NeuGly alpha 2 leads to 3Gal beta 1 leads to 3 (NeuAc alpha 2 leads to 6)GalNAc, and NeuGly alpha 2 leads to 3Gal beta 1 leads to 3(NeuGly alpha 2 leads to 6)GalNAc, and their partial desialized forms. The carbohydrate moieties of the factor X subgroups, factors X1 and X2, are identical.

Animals↗
PubMed1980

The asparagine-linked sugar chains of the glycoproteins in calf thymocyte plasma membrane. Structural studies of neutral oligosaccharides.

The neutral oligosaccharide fraction obtained from the hydrazinolysate of the plasma membrane glycoproteins of calf thymocytes was shown to be a mixture of twelve oligosaccharides. Oligosaccharides A, B, and C, which released galactose on treatment with jack bean beta-galactosidase but not with diplococcal beta-galactosidase, were shown to have the structures Gal beta 1-3Gal beta 1-4GlcNAc beta 1-4(Gal beta 1-3Gal beta 1-4GlcNAc beta 1-2)Man alpha 1-6(3)[Gal beta 1-3Gal beta 1-4GlcNAc beta 1-6(Gal beta 1-3Gal beta 1-4GlcNAc beta 1-2)Man alpha 1-3(6)]Man beta 1-4GlcNAc beta 1-4(Fuc alpha 1-6)GlcNAc, Gal beta 1-3Gal beta 1-4GlcNAc beta 1-4(Gal beta 1-3Gal beta 1-4GlcNAc beta 1-2)Man alpha 1-6(3)[Gal beta 1-3Gal beta 1-4GlcNAc beta 1-2Man alpha 1-3(6)]Man beta 1-4GlcNAc beta 1-4(Fuc alpha 1-6)GlcNAc, and Gal beta 1-3Gal beta 1-4GlcNAc beta 1-2Man alpha 1-6(Gal beta 1-3Gal beta 1-4GlcNAc beta 1-2Man alpha 1-3)Man beta 1-4GlcNAc beta 1-4(Fuc alpha 1-6)GlcNAc, respectively. Oligo saccharides D and E, which released galactose on treatment with either jack bean beta-galactosidase or diplococcal beta-galactosidase, were shown to have the structures Gal beta 1-4GlcNAc beta 1-2Man alpha 1-(Gal beta 1-4GlcNAc beta 1-2Man alpha 1-3)Man beta 1-4GlcNAc beta 1-4(Fuc alpha 1-)GlcNAc and Gal beta 1-4GlcNAc beta 1-2Man alpha 1-(GlcNAc beta 1-2Man alpha 1-3)Man beta 1-4GlcNAc beta 1-4(Fuc alpha 1-)GlcNAc, respectively. Five oligosaccharides (F1, G, H1, I, and J) were shown to have typical high-mannose type structures (Man alpha 1-)n.Man beta 1-4GlcNAc beta 1-GlcNAc, with n-values of 8, 7, 6, 5, and 4, respectively. The structures of the remaining two oligosaccharides F2 and H2 were elucidated as GlcNAc beta 1-2Man alpha 1-(GlcNAc beta 1-2Man alpha 1-3)Man beta 1-4GlcNAc beta 1-4(Fuc alpha 1-)GlcNAc and Man alpha 1-(Man alpha 1-)Man beta 1-(GlcNAc beta 1-Man alpha 1-)Man beta 1-GlcNAc beta 1-GlcNAc, respectively.

Animals↗
PubMed1980

Structural studies of the sugar chains of cold-insoluble globulin isolated from human plasma.

The asparagine-linked sugar chains of cold-insoluble globulin isolated from human plasma were released as oligosaccharides from the polypeptide moiety by hydrazinolysis. These oligosaccharides were N-acetylated and could be labeled by reduction with NaB[3H]4. The yield of radioactive oligosaccharides indicated that the glycoprotein has four asparagine-linked sugar chains in one molecule. More than 90% of the radioactive oligosaccharides contain N-acetylneuraminic acid, and could be separated into two acidic oligosaccharides, A-1 and A-2. By sequential exoglycosidase digestion in combination with methylation studies, their structures were elucidated as Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3) Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc and NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6 (NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2 Man alpha 1 leads to 3)-Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc.

Carbohydrate Sequence↗
PubMed1980

Structure of the asparagine-linked sugar chains of alpha-fetoprotein purified from human ascites fluid.

alpha-Fetoprotein purified from human serum was found to contain an asparagine-linked sugar chain in one molecule. The sugar chain was quantitatively released from the polypeptide moiety by hydrazinolysis and recovered as oligosaccharides after N-acetylation. The oligosaccharide mixture was separated into a neutral (N) and two acidic (A-1 and A-2) fractions by paper electrophoresis. By combination of sequential exoglycosidase digestion, methylation analysis, and concanavalin A-Sepharose column chromatography, the structures of these fractions were determined to be: Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3)Man beta 1 leads to 4GLcNAc beta 1 leads to 4(+/- Fuc alpha 1 leads to 6)GlcNAc; Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc beta 1 leads to 4(+/- Fuc alpha 1 leads to 6(GlcNAc; and NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc beta 1 leads to 4(+/- Fuc alpha 1 leads to 6)GlcNAc.

Ascitic Fluid↗
PubMed1980

Asparagine-linked sugar chains of glycoproteins in calf thymocyte plasma membrane. Isolation and fractionation of oligosaccharides liberated by hydrazinolysis.

The plasma membrane glycoproteins of calf thymocytes were converted to glycopeptides by exhaustive pronase digestion. Glycopeptides with asparagine-linked sugar chains were separated from those with mucine-type sugar chains by Bio-Gel P-10 column chromatography. The asparagine-linked sugar chains were released as oligosaccharides from the peptide moiety by hydrazinolysis and labeled by reduction with NaB[3H]4. The radioactive oligosaccharides were fractionated into fifteen acidic components and ten neutral components by combination of paper electrophoresis and Bio-Gel P-4 column chromatography. The acidic nature of all fifteen acidic components can be ascribed to their N-acetylneuraminic acid residues. The Bio-Gel P-4 column chromatographic patterns of the neutral oligosaccharide fraction and of the neutral fraction obtained on sialidase treatment of the pooled acidic oligosaccharide fraction were totally different, indicating that the acidic oligosaccharides are not simple sialyl derivatives of the neutral oligosaccharides.

Animals↗
PubMed1980

Structural study of the carbohydrate moiety of bovine pancreatic ribonuclease B.

The sugar chain of bovine pancreatic ribonuclease B was released from the polypeptide moiety by hydrazinolysis and by endo-beta-N-acetylglucosaminidase H digestion, and reduced with NaB[3H]4 after N-acetylation. The radioactive oligosaccharide mixtures thus obtained were fractionated by Bio-Gel P-4 column chromatography, and their structures were studied by sequential exoglycosidase digestion, methylation study, periodate oxidation and acetolysis. The results show that bovine pancreatic ribonuclease B has one of the following sugar chains as asparagine-linked carbohydrate. Formula (See Text).

Animals↗