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A Kobata

Publications and source records attributed to A Kobata.

At least 163 records · Page 9Linked to original sources
PubMed1985

Structures of the carbohydrate moieties of two monoclonal human lambda-type immunoglobulin light chains.

Human Bence Jones proteins of lambda type, Wh and Nei, both of which belong to subgroup II, contain an asparagine-linked sugar chain. Their carbohydrate moieties were liberated as oligosaccharides by hydrazinolysis and labeled by reduction with NaB3H4 after N-acetylation. Structural studies of each oligosaccharide by sequential exoglycosidase digestion in combination with methylation analysis revealed that Wh lambda contains the mono- and disialylated oligosaccharides (Formula: see text). These oligosaccharides are different from the oligosaccharides found in another lambda-type Bence Jones protein, Sm lambda, by Chandrasekaran et al. [Chandrasekaran, E. V., Mendicino, A., Garver, F. A., & Mendicino, J. (1981) J. Biol. Chem. 256, 1549-1555] and Garver et al. [Garver, F. A., Chang, L. S., Kiefer, C. R., Mendicino, J., Chandrasekaran, E. V., Isobe, T., & Osserman, E. F. (1981) Eur. J. Biochem. 115, 643-652].

Antibodies, Monoclonal↗
PubMed1985

Structural studies on the carbohydrate moieties of rat liver cathepsins B and H.

Cathepsins B and H from rat liver contain one asparagine-linked sugar chain in each molecule. The sugar chains were liberated from the polypeptide portions by hydrazinolysis followed by N-acetylation and NaB3H4 reduction. Paper electrophoresis of the radioactive oligosaccharide fractions revealed that they were mixtures of neutral oligosaccharides only. After fractionation by gel filtration the structure of each oligosaccharide was studied by sequential exoglycosidase digestion in combination with methylation analysis. The sugar chain of cathepsin H was a high mannose type oligosaccharide which varied in size from 5 to 9 mannose residues; on the other hand the major oligosaccharide of cathepsin B was a tetrasaccharide whose structure was Manalpha 1----6Manbeta 1----4GlcNAcbeta 1----4GlcNAc.

Animals↗
PubMed1985

Comparison of carbohydrate structure between human chorionic gonadotropin present in urine of patients with trophoblastic diseases and healthy individuals.

Human chorionic gonadotropin (hCG) highly purified from the urine of patients with trophoblastic diseases (choriocarcinoma and hydatidiform mole) and from healthy pregnant women contains four asparagine-linked sugar chains in one molecule. Comparative studies of the sugar chains released by hydrazinolysis revealed that the structures of the sugar chains of choriocarcinoma hCGs are quite different from those of mole and normal hCGs. The carbohydrate structures of mole hCGs are the same as those of normal hCG, while all choriocarcinoma hCGs examined contain two triantennary, two unusual biantennary, and one monoantennary complex-type sugar chains which are not found in normal hCGs. The triantennary and unusual biantennary sugar chains contain the +/- NeuAc alpha 2----Gal beta 1----4GlcNAc beta 1----4Man alpha 1----3 group in common. The total amounts of fucosylated sugar chains in choriocarcinoma hCGs are twice those found in the hCGs of other groups. Therefore, the appearance of the N-acetylglucosaminyl transferase responsible for the formation of the GlcNAc beta 1----4Man alpha 1----3 group and the increase of the fucosyl transferase responsible for the formation of the Fuc alpha 1----6 GlcNAc----Asn group appear to be specific characteristics of malignant transformation of the trophoblast, and the structural changes of sugar chains could serve as useful markers for the diagnosis of choriocarcinoma.

Carbohydrate Sequence↗
PubMed1985

Detection of incompletely sialylated human chorionic gonadotropin by peanut agglutinin in choriocarcinoma.

Human chorionic gonadotropin (hCG) in normal pregnancy and hydatidiform mole did not bind to the peanut agglutinin (PNA)-Sepharose column, whereas significant amount of hCG in choriocarcinoma adsorbed to the column. Therefore, PNA-Sepharose affinity chromatography is an effective tool for the detection of desialylated hCG and may be useful also for the diagnosis of choriocarcinoma.

Arachis↗
PubMed1984

Purification of hamster melanoma tyrosinases and structural studies of their asparagine-linked sugar chains.

In cultured melanotic melanoma, a marked decrease of pigmentation has been found to be induced by the addition of tunicamycin [Y. Mishima and G. Imokawa (1983) J. Invest. Dermatol. 81, 106-114]. Since it appears that this impaired pigmentation arises from the loss of asparagine-linked sugar chains serving as a signal for transport of tyrosinase from GERL (Golgi-associated endoplasmic reticulum of lysosomes) to premelanosomes, tyrosinases from the membrane fraction of Greene's hamster melanoma have been purified, and the structures of their sugar chains have been analyzed. Two kinds of tyrosinases were purified by Triton X-100 solubilization; DEAE-cellulose, Sephadex G-200, and DEAE-Sephadex column chromatography; and preparative polyacrylamide gel electrophoresis. The two tyrosinases were separated by polyacrylamide gel electrophoresis, and both corresponded to Mr 69,000. Their asparagine-linked sugar chains were released by hydrazinolysis and analyzed. The sugar chains of the two tyrosinases were identical except for the sialic acid contents. One mole of each tyrosinase contained 1 mol of high-mannose-type sugar chains and 3 mol of complex-type sugar chains. The former chain has Man3 approximately 5 X GlcNAc2 and the latter has Man3 X GlcNAc beta 1----4(+/- Fuc alpha 1----6)GlcNAc as their core structures. The complex-type sugar chains are composed of mono-, bi-, tri-, and tetraantennary sugar chains, with +/- Sia alpha 2----3Gal beta 1----4GlcNAc beta 1----as their outer chains.

Animals↗
PubMed1984

Changes in asparagine-linked sugar chains of human promyelocytic leukemic cells (HL-60) during monocytoid differentiation and myeloid differentiation. Decrease of high-molecular-weight oligosaccharides in acidic fraction.

Asialo-oligosaccharides obtained by sialidase digestion of asparagine-linked acidic sugar chains of promyelocytic leukemic cells (HL-60) differed in size distribution from those of cells induced to undergo myeloid or monocytoid differentiation. High-molecular-weight oligosaccharides which are predominant in HL-60 cells, decreased slightly during myeloid differentiation and markedly during monocytoid differentiation with concomitant increase of biantennary oligosaccharides. Structural analyses revealed that the induced monocytoid cells contain a series of complex-type oligosaccharides with bi-, tri-, and tetraantennary structures and high-molecular-weight oligosaccharides with N-acetyllactosamine repeating units, which show diversity in the presence or absence of the fucose residue linked to the reducing terminal N-acetylglucosamine, of the bisecting N-acetylglucosamine residue, and of the X-antigenic determinant in their outer chain moieties. Methylation analysis of each class of oligosaccharides of HL-60 cells and of their differentiated counterparts revealed the presence of similar heterogeneity in their structures, indicating that the difference is only quantitative. The results show that the shifts in size of the oligosaccharides found in the differentiated cells are derived from changes in outer chain formation and elongation of N-acetyllactosamine repeating units, and thus suggests that the decreased expression of N-acetylglucosaminyltransferases may be involved especially in the monocytoid differentiation program.

Asparagine↗
PubMed1984

Changes in asparagine-linked sugar chains of human promyelocytic leukemic cells (HL-60) during monocytoid differentiation and myeloid differentiation. Appearance of high mannose-type oligosaccharides in neutral fraction.

Structural changes in the asparagine-linked sugar chains of plasma membrane glycoproteins during myeloid and monocytoid differentiation were investigated by the use of an in vitro differentiation system for human promyelocytic leukemic cells (HL-60), which can be induced to more mature myeloid cells by exposure to dimethyl sulfoxide and to macrophage-like cells by a phorbol ester. The asparagine-linked sugar chains released from their plasma membranes by hydrazinolysis were separated into a neutral fraction and an acidic fraction composed of over ten components. The content of neutral oligosaccharides, which accounted for 8% of the total asparagine-linked sugar chains in HL-60 cells, increased slightly to 13% in dimethyl sulfoxide-induced cells and markedly to 33% in phorbol ester-induced cells. Structural analyses revealed that the neutral oligosaccharides of HL-60 cells are all of the complex type with a variety of Gal beta 1----4GlcNAc beta 1----units in their outer chain moieties and the following core structure: (sequence; see text) After myeloid and monocytoid differentiation, the total amount of neutral complex-type sugar chains did not change significantly, but newly found high mannose-type sugar chains contributed up to 3% and 24% of the total sugar chains, respectively.

Asparagine↗
PubMed1984

Comparative study of the oligosaccharides released from baby hamster kidney cells and their polyoma transformant by hydrazinolysis.

The asparagine-linked sugar chains of the membrane of baby hamster kidney cells and their polyoma transformant were quantitatively released as oligosaccharides by hydrazinolysis and labeled by NaB3H4 reduction. The radioactive oligosaccharides thus obtained were fractionated by paper electrophoresis. The neutral oligosaccharides of both cells were exclusively of high mannose type. The acidic oligosaccharides were bi-, tri-, and tetraantennary complex-type sugar chains with Man alpha 1----6 (Man alpha 1----3) Man beta 1----4 GlcNAc beta 1----4 (+/- Fuc alpha 1----6) GlcNAc as their cores and Gal beta 1----4 GlcNAc and various lengths of Gal beta 1----4 GlcNAc repeating chains in their outer-chain moieties. Prominent features of these acidic oligosaccharides are that all sialic acid residues were N-acetylneuraminic acid and were linked exclusively at C-3 of the nonreducing terminal galactose residues of the outer chains. Comparative study of oligosaccharides of the two cells by Bio-Gel P-4 column chromatography revealed that transformation of baby hamster kidney cells leads to a reduction in high mannose-type oligosaccharides and an increase in tetraantennary oligosaccharides. Increase of the outer chains linked at C-6 of the Man alpha 1----6 residue of the core is the cause of increase in the relative amount of highly branched oligosaccharides in the polyoma transformant.

Animals↗
PubMed1984

Structure of the N-asparagine-linked oligosaccharide units of human placental beta-glucocerebrosidase.

The N-asparagine-linked oligosaccharide chains of homogeneous human placental beta-glucocerebrosidase were released by hydrazinolysis, and their structures were analyzed. The sequence of sugars, linkage, and anomeric configuration of the glycosidic bonds were determined. Approximately 20% of the released sugar chain was of the typical high mannose type. The balance was of complex type with biantennary and triantennary structures. As a major component, the following trisialylated oligosaccharide was detected: (formula; see text).

Asparagine↗
PubMed1984

Sialic acid-containing sugar chains of hen ovalbumin and ovomucoid.

The acidic oligosaccharide fractions released from hen ovalbumin and ovomucoid by hydrazinolysis contain both sialyloligosaccharides and sulfated oligosaccharides. The sialyloligosaccharides were converted into neutral oligosaccharides by sialidase digestion, and separated from sulfated oligosaccharides by paper electrophoresis. Structural studies of these neutral oligosaccharides showed that the oligosaccharides of ovalbumin have different structural characteristics from those of ovomucoid, i.e., all sialyloligosaccharides from ovomucoid contain a pentasaccharide, alpha-D-Manp-(1----3)-[alpha-D-Manp-(1----6)]-beta-D-Manp -(1----4)-GlcpNAc- (1----4)-GlcpNAc, as a common core, and the smallest oligomannosyl core of the sugar chains from ovalbumin is alpha-D-Manp-(1----3)-alpha-D-Manp-(1----6)-[alpha-D-Manp -(1----3)]-beta-D- Manp-(1----4)-GlcpNAc-(1----4)-GlcpNAc. By methanolysis followed by N-acetylation, sialyl oligosaccharides, free from sulfated oligosaccharides, were recovered quantitatively from the acidic fractions of ovalbumin and ovomucoid. Methylation analysis of these sialyloligosaccharide mixtures, before and after sialidase digestion, showed that all sialic acid of both glycoproteins occurs as a alpha-Sia-(2----3)-D-Galp group.

Animals↗
PubMed1984

New evidence of the substrate specificity of endo-beta-N-acetylglucosaminidase D.

The susceptibility of a variety of oligosaccharides to endo-beta-N-acetylglucosaminidase D was investigated. The oligosaccharides having the structures of Man alpha 1----6 (GlcNAc beta 1----4Man alpha 1----3)Man beta 1----4GlcNAc beta 1----4(+/- Fuc alpha 1----6)GlcNAcOT, derived from complex type triantennary sugar chains, released +/- Fuc alpha 1----6GlcNAcOT upon incubation with the enzyme at almost the same rate as Man alpha 1----6(Man alpha 1----3)Man beta 1----4GlcNAc beta 1----4GlcNAcOT. When the reaction products were reduced with NaB3H4 and analyzed by Bio-Gel P-4 column chromatography, a new radioactive peak was detected in both cases. This new radioactive oligosaccharide was confirmed to be Man alpha 1----6(GlcNAc beta 1----4Man alpha 1----3)Man beta 1----4GlcNAcOT in the former case and Man alpha 1----6(Man alpha 1----3)Man beta 1----4GlcNAcOT in the latter. These results indicated that endo-beta-N-acetylglucosaminidase D does not require the presence of a free hydroxyl group at the C-4 position of the alpha-mannosyl residue of the trisaccharide glycon: Man alpha 1----3Man beta 1----4GlcNAc beta 1----.

Acetylglucosaminidase↗
PubMed1984

Application of a Phaseolus vulgaris erythroagglutinating lectin agarose column for the specific detection of human hepatoma gamma-glutamyl transpeptidase in serum.

By making use of the structural change of the sugar chains of liver gamma-glutamyl transpeptidase associated with malignant transformation, a new method has been developed to distinguish human serum gamma-glutamyl transpeptidase associated with primary hepatoma from that of non-hepatoma patients. In principle, the method consists of affinity chromatography of the desialylated serum enzyme on a Phaseolus vulgaris erythroagglutinating lectin agarose column.

Carcinoma, Hepatocellular↗
PubMed1984

[Structural change of sugar chains of glycoproteins by cell transformation and its application to the diagnosis of cancer].

Comparative study by using hydrazinolysis has revealed that the carbohydrate moieties of gamma-glutamyl transpeptidases purified from rat liver and rat AH-66 hepatoma are quite different. The sugar chains of the liver enzyme were all acidic, while 29% of those of hepatoma enzyme was neutral. Three prominent structural differences were found in the acidic sugar chains of the two enzymes: 1) The liver enzyme has asparagine-linked sugar chains with complete outer chain, NeuAc alpha----Gal beta 1----4GlcNAc, while hepatoma enzyme has sugar chains incomplete in their outer chain moieties; 2) Gal beta 1----4GlcNAc beta 1----4GlcNAc group is found in the sugar chains of liver enzyme but not in those of hepatoma enzyme; 3) More than 40% of the sugar chains of hepatoma enzyme contain bisecting N-acetylglucosamine which is not found in those of liver enzyme.

Animals↗
PubMed1984

Structure of the sugar chain of alphafetoprotein purified from a human yolk sac tumor and its reactivity with concanavalin A.

We have attempted to determine the carbohydrate moiety of human alphafetoprotein (AFP) produced by a yolk sac tumor. AFP was obtained from the cystic fluid of human yolk sac tumors grown in nude mice and was purified using an immunoadsorbent column coupled with monoclonal anti-AFP antibody. Then, the carbohydrate chain of the purified AFP was quantitatively released from the polypeptide chain. The resulting oligosaccharide was labeled and, by sequential exoglycosidase digestion in combination with methylation analysis and periodate oxidation, the structure was determined to be: Sia alpha 2----6Gal beta 1----4GlcNAc beta 1----2Man alpha 1----6 (GlcNAc beta 1----4) (Sia alpha 2----6Gal beta 1----4GlcNAc beta 1----2Man alpha 1----3) Man beta 1----4GlcNAc beta 1----4 (Fuc alpha 1----6) GlcNAcOT Compared with the known structure of the sugar, chain of human hepatic AFP, it was found that the sugar chain of yolk sac AFP contained an additional sugar, N-acetylglucosamine (bisect GlcNAc) linked to the beta-mannose. In the light of recent knowledge, this result indicates that the Concanavalin A (Con-A) binding site of the sugar chain is blocked by this GlcNAc in human yolk sac AFP. This fact forms the basis for the clinical use of the Con-A binding test to determine the origin of AFP in patients.

Adult↗
PubMed1983

Structural determinants of Phaseolus vulgaris erythroagglutinating lectin for oligosaccharides.

The behaviors of oligosaccharides obtained by hydrazinolysis of asparagine-linked sugar chains in an erythroagglutinating phytohemagglutinin lectin-agarose column were examined to define the structural determinants required for the interaction of asparagine-linked sugars with erythroagglutinating phytohemagglutinin. The minimal structural unit required for erythroagglutinating phytohemagglutinin binding was (formula; see text) in which R1 and R2 represent either hydrogen or sugars and R3 represents either GlcNAc leads to Asn or (Fuc alpha 1 leads to 6)GlcNAcOT.

Carbohydrate Conformation↗
PubMed1983

Structures of the asparagine-linked sugar chains of human chorionic gonadotropin produced in choriocarcinoma. Appearance of triantennary sugar chains and unique biantennary sugar chains.

Human chorionic gonadotropin (hCG) highly purified from urine of the patient with choriocarcinoma contains four asparagine-linked sugar chains in one molecule. The sugar chains were quantitatively liberated as radioactive oligosaccharides from polypeptide portion by hydrazinolysis followed by N-acetylation and NaB3H4 reduction. The structures of these sugar chains were determined by the combination of sequential glycosidase digestion, periodate oxidation, and methylation analysis. As compared with the sugar chains of normal urinary and placental hCG reported previously, they include several prominent structural differences. More than 97% of the sugar chains of choriocarcinoma hCG was free from sialic acid, while the sugar chains of normal hCG were mostly sialylated. Choriocarcinoma hCG contains unusual biantennary complex-type sugar chains in addition to regular tri-, bi-, and monoantennary sugar chains. These sugar chains have two outer chains linked at the C-2 and C-4 positions of the same alpha-mannosyl residue of the trimannosyl core. Since normal hCG does not contain any triantennary sugar chains, occurrence of Gal beta 1 leads to 4GlcNAc beta 1 leads to 4Man alpha 1 leads to group is another characteristic feature of the sugar chains of choriocarcinoma hCG. The evidence that the monoantennary sugar chain of Man 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 leads to Asn is not found in normal hCG and the sum total of fucosylated sugar chains is 50%, which is twice as much as normal hCG, indicated that fucosylation is also modified in choriocarcinoma tissue.

Adult↗
PubMed1983

Sulfated asparagine-linked sugar chains of hen egg albumin.

The fraction of hen egg albumin glycopeptides mixture, which passes through a Dowex 50-H+ column, contains two sulfate-containing glycopeptides. Based on the structural studies of oligosaccharides released from the glycopeptides by hydrazinolysis, their structures were elucidated as follows. (formula; see text)

Animals↗