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Biomedical subjects

S Hase

Publications and source records attributed to S Hase.

At least 163 records · Page 9Linked to original sources
PubMed1979

Tagging of sugars with a fluorescent compound, 2-aminopyridine.

Potential aldehyde groups of several monosaccharides and oligosaccharides were coupled with 2-aminopyridine by reductive amination with sodium cyanoborohydride. The product was isolated by adsorption on a Dowex 50 (H+) column, followed by washing, elution with aqueous ammonia and evaporation. The specimen was analyzed by paper electrophoresis at pH 5.0. Each sugar derivative gave a single spot in addition to one corresponding to excess 2-amino-pyridine when the paper was scanned under a UV lamp. The migration rates of these fluorescent sugars were related to their molecular weights and were independent of their linkage points and anomeric configurations. The reducing end sugar units of oligosaccharide derivatives could be identified by gas-liquid chromatography after hydrolysis of the 2-aminopyridine derivatives of the oligosaccharides.

Aminopyridines↗
PubMed1979

Analyses of oligosaccharides by tagging the reducing end with a fluorescent compound. I. Application to glycoproteins.

The reducing end sugar of an oligosaccharide and 2-aminopyridine were linked by means of reductive amination with sodium cyanoborohydride. The fluorescent derivative of the oligosaccharide thus obtained, which had a positive charge, was subjected to two-dimensional paper electrophoresis. In the first direction, the sugar derivative moved according to its degree of polymerization, and in the second direction, it moved according to the structure of the borate complex. In this way fluorescent derivatives of saccharides were mapped on a sheet of paper. The method was applied to some known mono- and oligosaccharides and to the saccharides obtained by nitrous deamination of the oligosaccharide portions of glycoproteins (fetuin, Take-amylase A, and ovalbumin). The fingerprints thus obtained were characteristic of the chemical structures of the original oligosaccharides.

Aminopyridines↗
PubMed1977

The chemical structure of the lipid A component of lipopolysaccharides from Chromobacterium violaceum NCTC 9694.

The chemical structure of the lipid A component of lipopolysaccharides from Chromobacterium violaceum NCTC9694 was studied. Sequential treatment of lipopolysaccharide with alkali, acid, sodium borohydride and hydrazine allowed the isolation of a reduced glucosamine disaccharide. According to methylation studies and enzymic analysis with beta-N-acetylglucosaminidase the D-glucosamine residues are beta(1 leads to 6) linked. The disaccharide carries two phosphate groups, one being linked glycosidically, the other being linked as an ester to the non-reducing glucosamine. Application of a different degradation pathway shows that the ester-bound phosphate group is substituted by a 4-aminoarabinosyl residue and that the glycosidically linked phosphate group is substituted by a glucosaminyl residue. Neither the amino nor the hydroxyl groups of both these substituents are acylated. This backbone structure is shown in the following formula: (formula: see text). The amino groups of the central glucosamine disaccharide are substituted by D-3-hydroxy-dodecanoic acid, the hydroxyl groups by dodecanoic, L-2-hydroxydodecanoic and D-3-hydroxy-decanoic acid.

Acetylglucosamine↗
PubMed1977

Chemical structure of the lipid A component of lipopolysaccharides from Fusobacterium nucleatum.

The lipid A component of lipopolysaccharides from Fusobacterium nucleatum Fev 1 consists of beta-1',6-linked D-glucosamine disaccharides, which carry two phosphate groups: one in glycosidic and one in ester linkage. The amino groups of the glucosamine disaccharides are substituted by D-3-hydroxyhexadecanoic acid. The hydroxyl groups of the disaccharide backbone are acylated by tetradecanoic, hexadecanoic, and D-3-hydroxytetradecanoic acids. Part of the ester-bound D-3-hydroxytetradecanoic acid is 3-O-substituted by tetradecanoic acid. Whereas a similar pattern of fatty acids was detected in lipopolysaccharides from two other F. nucleatum strains, the amide-bound fatty acid in F. varium and F. mortiferum was D-3-hydroxytetradecanoic acid. The chemical relationships of lipid A from Fusobacteria and other gram-negative bacteria are discussed.

Chemical Phenomena↗
PubMed1977

The structure of the branching point between acidic polysaccharide and peptidoglycan in Micrococcus lysodeikticus cell wall.

An acidic polysaccharide fraction composed of glucose and N-acetylmannosaminuronic acid with a small portion of peptidoglycan was isolated by enzymic digestion and subsequent ECTEOLA-cellulose chromatography from the cell walls of Micrococcus lysodeikticus. On mild acid treatment, the fraction became Morgan-Elson positive and formed the Morgan-Elson chromogen on heating with phosphate buffer (pH 7). The product of mild acid treatment released inorganic phosphate on treatment with phosphomonoesterase. After gel-chromatography on Sephadex G-25 and DE-32, the acidic polysaccharide fraction contained less glucosamine than muramic acid. By reduction of this fraction with borohydride, a part of the glucosamine was converted into glucosaminitol. Based on these results, it is suggested that the acidic polysaccharide is linked to glucosamine by a (1-3) linkage, which is linked to the 6 position of a muramic acid residue by a phosphodiester linkage.

Amino Acids↗
PubMed1976

Methylation analysis of glucosaminitol and glucosaminyl-glucosaminitol disaccharides. Formation of 2-deoxy-2-(N-acetylacetamido)-glucitol derivatives.

N-Acetylglucosaminitol, N-acetylglucosaminyl-beta 1',4-N-acetylglucosaminitol (chitobiitol), the corresponding trimer (chitotriitol) and N-acetylgucosaminyl-beta 1'6-N-acetylglucosaminitol were subjected to methylation analysis using combined gas-liquid chromatography/mass spectrometry. The preparation were subjected to permethylation according to Hakomori, followed by acid hydrolysis, reduction and peracetylation. From N-acetylglucosaminitol and its 4-0 and 6-0 substituted derivatives, methylated N-acetylacetamido derivatives were obtained. The possible conditions for the formation of these products are discussed.

Acetylglucosamine↗
PubMed1976

Isolation and analysis of the lipid A backbone. Lipid A structure of lipopolysaccharides from various bacterial groups.

A degradation procedure of lipopolysaccharides was worked out which allows the isolation of the reduced backbone of lipid A in a total yield of between 20 and 30%. This procedure was applied to lipopolysaccharides of S forms (Salmonella minnesota, Shigella flexneri 5b, Escherichia coli 086, E. coli 0111, Xanthomonas sinensis, Rhodopseudomonas gelatinosa) and R mutants (Salmonella minnesota, Shigella flexneri, 5b, E. coli BB9 and E. coli EH 100). Chemical analysis, reaction with beta-N-acetyl-glucosaminidase and application of methylation analysis revealed that the lipid A backbone of all strains contains beta 1', 6-linked glucosamine disaccharides carrying two phosphate groups, one in glycosidic and one in ester linkage, a structure, identified previously in the Salmonella minnesota Re mutant.

Acetylglucosamine↗