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A Kobata

Publications and source records attributed to A Kobata.

At least 181 records · Page 10Linked to original sources
PubMed1983

The structures of the carbohydrate moieties of bovine blood coagulation factor IX (Christmas factor).

Bovine blood coagulation factor IX (Christmas factor) contains four 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. The structures of these sugar chains were determined by sequential exoglycosidase digestion in combination with methylation analysis. Bovine factor IX contained two unique penta- and tetrasialyl triantennary sugar chains with the structures shown below in addition to tetra-, tri-, and disialyl biantennary sugar chains of Sia alpha 2 leads to 3 Gal beta 1 leads 3(Sia alpha 2 leads to 6)GlcNAc beta 1 leads to 2Man alpha 1 leads to 6[Sia alpha 2 leads to 3Gal beta 1 leads to 3(Sia 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, Sia alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6[Sia alpha 2 leads to 3Gal beta 1 leads to 3(Sia 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 Sia alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(Sia 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 their partially desialized forms.

Acetylation↗
PubMed1983

Purification and molecular characterization of rat intestinal brush border membrane dipeptidyl aminopeptidase IV.

Dipeptidyl aminopeptidase IV (EC 3.4.14.-) was solubilized from a particulate membrane fraction of rat intestinal mucosa with Triton X-100. The solubilized enzyme was purified to homogeneity following ammonium sulfate fractionation, chromatography on DEAE-Sepharose and hydroxyapatite, gel filtration and preparative polyacrylamide gel electrophoresis. The final enzyme preparation had a specific activity of 55 units/mg protein representing a 1373 fold purification over the starting material. Purity was judged by polyacrylamide gel electrophoresis and double immunodiffusion. The molecular weight of the native undenatured enzyme was estimated to be 230000 by gel filtration and polyacrylamide gel electrophoresis. Electrophoresis under denaturing conditions (sodium dodecyl sulfate) indicated that the protein consists of two identical 98 kDa subunits. Dipeptidyl aminopeptidase IV is a glycoprotein containing approx. 8% carbohydrate by weight. A detailed analysis of the individual sugar components demonstrated that fucose, galactose, glucose, mannose, sialic acid and hexosamine sugars were present. The nature of the constituent asparagine linked oligosaccharide side chains was further examined following cleavage from the peptide backbone by hydrazinolysis. Following high voltage paper electrophoresis approx. 80% of the isolated oligosaccharide was found with the neutral fraction while the remaining 20% consisted of a single acidic component. Gel filtration of the neutral oligosaccharide fraction indicated that it contains approx. 19 sugar residues.

Amino Acids↗
PubMed1983

Structural studies of the sugar chains of hen ovomucoid. Evidence indicating that they are formed mainly by the alternate biosynthetic pathway of asparagine-linked sugar chains.

The carbohydrate moieties of hen ovomucoid were released as oligosaccharides by hydrazinolysis. The neutral oligosaccharide fraction which comprised about 85% of the total sugar was fractionated into eight oligosaccharide fractions by Bio-Gel P-4 column chromatography. Occurrence of novel penta-antennary oligosaccharides in the larger three fractions was reported in the preceding paper (Yamashita, K., Kamerling, J.P., and Kobata, A. (1982) J. Biol. Chem. 257, 12809-12814). Structural studies of the remaining smaller oligosaccharides indicated that they all have Man alpha 1 leads to 6(Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc as their common core. The alpha-mannosyl residues occur either free or as one of the following five groups: GlcNAc beta 1 leads to 2Man, GlcNAc beta 1 leads to 4Man, GlcNAc beta 1 leads to 4(GlcNAc beta 1 leads to 2)Man, GlcNAc beta 1 leads to 6(GlcNAc beta 1 leads to 2)Man, and GlcNAc beta 1 leads to 6(GlcNAc beta 1 leads to 4)(GlcNAc beta 1 leads to 2) Man. In most oligosaccharides, a beta-N-acetylglucosamine residue is linked at the C-4 position of the beta-mannosyl residue of the core. The structural characteristic of the sugar chains of hen ovomucoid indicated that they are not formed by the ordinary processing pathway of the asparagine-linked sugar chains.

Acetylglucosamine↗
PubMed1983

Structural studies of the carbohydrate moieties of rat kidney gamma-glutamyltranspeptidase. An extremely heterogeneous pattern enriched with nonreducing terminal N-acetylglucosamine residues.

The carbohydrate moieties of gamma-glutamyltranspeptidase purified from rat kidney were released as oligosaccharides by hydrazinolysis. Fractionation of the oligosaccharide mixture by paper electrophoresis and Bi-Gel P-4 column chromatography and structural study of each component by sequential exoglycosidase digestion in combination with methylation analysis and periodate oxidation have revealed that it is composed of 23 neutral oligosaccharides, monosialyl derivatives of 67 oligosaccharides, disialyl derivatives of 62 oligosaccharides, and trisialyl derivatives of 5 oligosaccharides. The neutral oligosaccharides are either high mannose type or biantennary complex type, and the acidic oligosaccharides are bi-, tri-, and tetranntennary complex type sugar chains. Most of the complex type sugar chains contain an N-acetylglucosamine residue at the C-4 position of the beta-mannosyl residue of their trimannosyl core. Another characteristic feature of these complex type sugar chains is that they are enriched with nonreducing terminal beta-N-acetylglucosamine residues.

Animals↗
PubMed1983

Carbohydrates of influenza virus hemagglutinin: structures of the whole neutral sugar chains.

The carbohydrates of BHA, a solubilized hemagglutinin of influenza virus by bromelain digestion, were quantitatively released as oligosaccharides by hydrazinolysis. The oligosaccharide mixture was separated into a neutral and two acidic fractions by paper electrophoresis. Both acidic fractions were resistant to sialidase digestion but were slowly converted to the neutral fraction by incubation with sulfatases. The neutral fraction which comprised about 80% in molar ratio of total oligosaccharides was separated into 13 oligosaccharides by paper chromatography and by Con A-Sepharose column chromatography. Structural studies of these oligosaccharides by sequential exoglycosidase digestion and by methylation analysis revealed that BHA contains a series of high mannose type and bi-, tri-, and tetraantennary complex type sugar chains. Occurrence of Gal beta l leads to 3GlcNAc outer chain in two and bisectional N-acetylglucosamine in one of the biantennary sugar chains is an interesting characteristic of the sugar chains of BHA.

Carbohydrate Conformation↗
PubMed1983

Organ-specific difference in the sugar chains of gamma-glutamyltranspeptidase.

Sugar chains of gamma-glutamyltranspeptidase purified from neonatal mouse liver and adult mouse kidney were quantitatively released as oligosaccharides from the polypeptide backbone by hydrazinolysis. A comparative study of the structures of the oligosaccharides has revealed that the GlcNAc beta 1 leads to 4Man beta 1 leads to group is found in the sugar chains of kidney enzyme but not in those of liver enzyme. This is considered as an organ-specific difference common to mammals because the same phenomenon was found in bovine and rat enzymes.

Acyltransferases↗
PubMed1983

Difference in the sugar chains of two subunits and of isozymic forms of rat kidney gamma-glutamyltranspeptidase.

A comparative study by gel-permeation chromatographic analysis of oligosaccharides released from the heavy and the light subunits of rat kidney gamma-glutamyltranspeptidase has revealed that high-mannose-type sugar chains are found only in the heavy subunit, and the nonsialylated and nonfucosylated biantennary complex-type sugar chains are included only in the light subunit. By the same analysis of the oligosaccharide fractions obtained from four isozymic forms of rat kidney gamma-glutamyltranspeptidase, it was found that all these enzymes contain 2 mol of neutral sugar chains but different numbers of acidic sugar chains. The total numbers of sialic acid residues showed a reciprocal relationship to the isoelectric point of each isozymic form, and an increase of 1 mol of sialic acid residue corresponds to a decrease of 0.5 in the value of the isoelectric point.

Animals↗
PubMed1983

The enzymatic cleavage of rhodopsin by the retinal pigment epithelium. II. The carbohydrate composition of the glycopeptide cleavage product.

The carbohydrate groups present in the glycopeptide cleaved from purified [3H]-GlcNAc-rhodopsin by an enzyme from the retinal pigment epithelium were analyzed in terms of the size of the oligosaccharide chains, the sequence of the sugars and their anomeric linkages. These analyses were performed also on intact rhodopsin and an enzyme control. The oligosaccharides were cleaved from the peptide by means of hydrazinolysis. After reduction with NaB3H4, the oligosaccharides, purified by paper electrophoretic and paper chromatographic means, were digested sequentially with exoglycosidases, and the resultant digestion products examined by high-resolution gel filtration on Bio-Gel P-4 (-400). The size, sequence and anomeric configuration of the constituents of the oligosaccharides present in the glycopeptide were essentially identical to those present in intact purified rhodopsin, indicating the retention by the glycopeptide of the sugar chains of the intact molecule.

Animals↗
PubMed1983

Carbohydrate structures of bovine kidney gamma-glutamyltranspeptidase.

The carbohydrate moieties of gamma-glutamyltranspeptidase (gamma-GTP) purified from bovine kidney were chemically released as oligosaccharides. The oligosaccharide mixture was fractionated into a neutral fraction and three groups of acidic fractions containing one, two, and three sialic acid residues. Both the neutral fractions and the neutral oligosaccharide mixture obtained from the pooled sample of all acidic fractions by sialidase treatment were separated into seven components by Bio-Gel P-4 column chromatography. Structural studies of these components by sequential exoglycosidase digestion in combination with methylation analysis indicated that the gamma-GTP contains at least twelve neutral sugar chains which are either the high mannose type, or the bi- and triantennary complex type, and thirteen acidic sugar chains of the bi-, tri-, and tetraantennary complex type. The characteristics feature of the sugar chains of the gamma-GTP is that most of the complex type sugar chains contain an N-acetylglucosamine residue at the C-4 position of the beta-mannosyl residue of their trimannosyl core, and their outer chain moieties are enriched in non-reducing terminal beta-N-acetylglucosamine residues.

Animals↗
PubMed1983

Comparative study of the sugar chains of gamma-glutamyltranspeptidases purified from rat liver and rat AH-66 hepatoma cells.

A comparative study using hydrazinolysis has revealed that the oligosaccharide pattern of gamma-glutamyltranspeptidase purified from rat AH-66 hepatoma cells is very different from that of the enzyme from rat liver. Studies of oligosaccharides in each fraction have clarified the structural basis of the difference found in the sugar chains of the two enzymes. The sugar chains of the liver enzyme were all acidic, while 28% of those of the hepatoma enzyme were neutral, the latter being composed of high-man-nose-type and complex-type sugar chains. Three prominent structural differences were found in the acidic sugar chains of the two enzymes: (a) the sugar chains of the liver enzyme have complete outer chains, Gal beta 1 leads to 4GlcNAc beta 1 leads to, while many of those of the hepatoma enzyme have incomplete outer chains without galactose (Gal); (b) the Gal beta 1 leads to 4GlcNAc beta 1 leads to Gal beta 1 leads to 4GlcNAc beta 1 leads to group is found in the sugar chains of the liver enzyme but not in those of the hepatoma enzyme; (c) more than 40% of the sugar chains of the hepatoma enzyme contain bisect N-acetylglucosamine (GlcNAc) residue which is not found in those of the liver enzyme. Furthermore, the total number of asparagine-linked sugar chains in one molecule of hepatoma enzyme was about 4 times that found in one molecule of liver enzyme.

Acyltransferases↗
PubMed1983

Sugar chain of alpha-fetoprotein produced in human yolk sac tumor.

The carbohydrate moiety of alpha-fetoprotein purified from human yolk sac tumors grown in nude mice was quantitatively released from the polypeptide chain as oligosaccharides by hydrazinolysis. The oligosaccharides were separated into a neutral and two acidic oligosaccharides by paper electrophoresis. By sequential exoglycosidase digestion in combination with per-O-methylation study and periodate oxidation, their structures were determined to be: Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(GlcNAc beta 1 leads to 4) (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)GlcNAcOT, Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(GlcNAc beta 1 leads to 4) (Sia 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)GlcNAcOT; and Sia alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(GlcNAc beta 1 leads to 4) (Sia 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 4 GlcNAc beta 1 leads to 4(Fuc alpha 1 leads to 6)GlcNAcOT, in which Gal is galactose, GlcNac is N-acetylglucosamine, Man is mannose, Fuc is fucose, Sia is sialic acid, and Subscript OT is the NaB3H4-reduced oligosaccharide.

Carbohydrate Sequence↗
PubMed1982

Structures of the asparagine-linked sugar chains of subcomponent C1q of the first component of bovine complement.

Bovine C1q, a subcomponent of the first component of complement, contains six asparagine-linked sugar chains in 1 molecule. The sugar chains are exclusively distributed in the noncollagenous regions. The sugar chains were liberated as radioactive oligosaccharides from the polypeptide portion by hydrazinolysis followed by N-acetylation and NaB[3H]4 reduction, and their structures were studied by sequential exoglycosidase digestion in combination with methylation analysis. Bovine C1q was shown to contain equal amounts of neutral and acidic oligosaccharides with the following structures: (formula, see text) where NeuG1 is N-glycolylneuraminic acid.

Animals↗
PubMed1982

Structural study of the carbohydrate moiety of hen ovomucoid. Occurrence of a series of pentaantennary complex-type asparagine-linked sugar chains.

Hen ovomucoid contains a series of novel pentaantennary complex-type asparagine-linked sugar chains which can be classified into three groups, N-1, N-2, and N-3b, N-3b, the structure of which is found as a common (formula, see text) structure in all pentaantennary sugar chains. N-2 is a mixture of three isomeric monogalactosyl derivatives of N-3b, and N-1 is a mixture of two isomeric digalactosyl derivatives of N-3b. Most of the galactoses are beta-linked at the C-4 position of beta-N-acetylglucosamine residues 2 and 4 in the N-3b structure shown above. Small amounts of the galactoses are also linked at the C-4 position of beta-N-acetylglucosamine residue 3.

Animals↗
PubMed1982

Structures of the carbohydrate moieties of secretory component purified from human milk.

Secretory component purified from human milk contains four asparagine-linked sugar chains in one molecule. The sugar chains were released from the polypeptide portion of secretory component by hydrazinolysis as oligosaccharides and fractionated by paper electrophoresis and paper chromatography. The sugar chains of secretory component show an extraordinarily high multiplicity. By sequential exoglycosidase digestion in combination with methylation analysis, more than 40 structurally different sugar chains were found. They were all of biantennary complex type with either Man alpha 1 leads to 6(Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNac beta 1 leads to 4GlcNAc or Man alpha 1 leads to 6(Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc beta 1 leads to 4(Fuc alpha 1 leads to 6)GlcNAc as their core portions and the multiplicity is produced by variety of the two outer chain moieties. The structures of outer chains found are GlcNAc beta 1 leads to 2, +/- NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2, Gal beta 1 leads to 4(Fuc alpha 1 leads to 3)GlcNAc beta 1 leads to 2, GL beta 1 leads to 4GlcNAc beta 1 leads to 3Gal beta 1 leads to 4(+/- Fuc alpha 1 leads to 3)GlcNAc beta 1 leads to 2, NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 3 Gal beta 1 leads to 4GlcNAc beta 1 leads to 2, Gal beta 1 leads to 4(Fuc alpha 1 leads to 3)GlcNAc beta 1 leads to 3Gal beta 1 leads to 4(Fuc alpha 1 leads to 3)GlcNAc beta 1 leads to 2, and NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 3Gal beta 1 leads to 4(Fuc alpha 1 leads to 3)GlcNAc beta 1 leads to 2.

Carbohydrate Sequence↗