Structure of the polysaccharide antigen of Eubacterium saburreum, strain L44

Synthesis of an unusual hexasaccharide repeating unit from the cell wall polysaccharide of Eubacterium saburreum strain T19

Eubacterium saburreum is one of the human oral pathogens and has been proved to play a significant role in the development of periodontal diseases.

The structure of the antigenic polysaccharide produced by Eubactrium saburreum T15

The antigenic polysaccharide was obtained from the cell wall of Eubacterium saburreum strain T15 by trypsin digestion followed by gel permeation and ion-exchange chromatography. Its structure was determined using acid hydrolysis, methylation analysis, and 1D and 2D NMR spectroscopy. It contained L-threo-pent-2-ulose (Xul), D-fucose (Fuc), and D-glycero-D-galacto-heptose (Hep) in 2:3:3 ratio. Methylation analysis indicated an octasaccharide repeating-unit containing five branches. The 1H and 13C signals in NMR spectra of the sugar residues were assigned by COSY, HOHAHA, and HMQC 2D experiments, and the sequence of sugar residues in the repeating unit was determined by NOESY and HMBC experiments. The polysaccharide also contains two O-acetyl groups in the repeating unit, located on the Hep residue. The repeating structure can be written as: [see text for equation]. This is a novel structure in bacterial cell-wall polysaccharides from Gram-positive bacteria.

Structural studies of the antigenic polysaccharide of Eubacterium saburreum, strain T19

The antigenic polysaccharide produced by Eubacterium saburreum, strain T19, contains unusual sugars, including D-glycero-D-galacto-heptose (Hep) and D-fucose (D-Fuc). A repeating unit of the polysaccharide is composed of a linear chain of D-glycero-D-galacto-heptopyranosyl tetrasaccharide as its backbone structure, i.e., -[-->6)-beta-Hep p-(1-->3)-beta-Hep p-(1-]2-->, and a D-fucofuranosyl disaccharide as a branched group, i.e., alpha-D-Fuc f-(1-->2)-alpha-D-Fuc f-(1-->, which is linked to O-4 of one (1--6)-linked D-glycero-D-galacto-heptopyranosyl residue. The polysaccharide also contains O-acetyl groups.

Immunochemical and structural characterization of the antigenic polysaccharide from Eubacterium saburreum T18

An antigenic surface polysaccharide produced by Eubacterium saburreum strain T18, isolated from human dental plaque, was purified from formamide extract of whole cells. Methylation analysis, Smith degradation, optical rotation data and nuclear magnetic resonance spectra demonstrated that the purified antigen was a homopolysaccharide composed of D-glycero-D-galacto-heptose (Hep.) residues. The structure of the repeating unit in the polysaccharide was: -[----6)-[alpha-Hep.furanosyl-(1----4)]-beta-Hep.pyranosyl- (1----6)-[alpha-Hep.furanosyl-(1----2), alpha-Hep.furanosyl-(1----4)]-beta- Hep.pyranosyl-(1-)4----6)-beta-Hep.pyranosyl-(1----. No heptose residues were acetylated. Immunodiffusion reactions in agar gel suggested that the immunodeterminant of the antigenic polysaccharide was D-glycero-D-galacto-heptofuranosyl residues as branched nonreducing terminals.

Chemical composition and immunological characterization of polysaccharide antigen from Eubacterium saburreum T18

Two types of polysaccharide were obtained from the oral microorganism Eubacterium saburreum T18 by formamide extraction and subsequent gel filtration and ion-exchange chromatography. One polysaccharide, which was composed of D-glycero-D-galacto-heptose, had antigenic activity in an immunoprecipitation reaction with rabbit anti-T18 serum due to immunoglobulin M antibodies. The second polysaccharide was composed of D-glycero-D-manno-heptose and L-rhamnose, but it did not have immunoprecipitation activity. These polysaccharide antigens were not alkali labile and differed from E. saburreum L44 and T27 antigens, which were composed of D-glycero-D-galacto-heptose.

Structural studies of the antigenic polysaccharide of Eubacterium saburreum, strain T17

The antigenic polysaccharide produced by Eubacterium saburreum, strain T17, is a homoglycan composed of D-glycero-D-galacto-heptose (Hep) residues having the pentasaccharide repeating-unit----6)-[alpha-Hepf-(1----4)] -beta-Hepp-(1----6)-[alpha-Hepf-(1----2), alpha-Hepf-(1----4)]-beta-Hepp-(1----. The polysaccharide does not contain O-acetyl group.

Structural studies of the antigenic polysaccharide of Eubacterium saburreum, strain T27

The antigenic polysaccharide produced by Eubacterium saburreum, strain T27, is a homoglycan composed of D-glycero-D-galacto-heptose (Hep) residues having a nonasaccharide repeating-unit with the structure (leads to 6)-[alpha-Hepf-(1 leads to 4)]-beta-Hepp-(1) leads to (3)6)-[alpha-Hepf-(1 leads to 2), alpha-Hepf-(1 leads to 4)]-beta-Hepp-(1 leads to. The polysaccharide contains acetyl groups linked to O-2 (except to the 2,4,6-linked heptopyranosyl residue), O-3 and O-7 of part of both heptopyranosyl and heptofuranosyl residues. The assignment of an acetyl group at O-3 of part of the terminal heptofuranosyl and 4,6-linked heptopyranosyl groups is tentative.

Eubacterium saburreum L13 antigen containing a ketohexose as a main sugar constituent

A periodate-resistant antigen (PS L13) which contained ketohexose and glucose was isolated from the oral microorganism Eubacterium saburreum L13 by trypsin digestion and subsequent gel filtration and ion-exchange chromatography. The ketohexose reacted as fructose would in colorimetric and chromatographic analyses, but not in gas-liquid chromatography. Rabbit antiserum to E. saburreum L13 agglutinated the bacteria and contained precipitins of the immunoglobulin G class specific for PS L13.

Isolation and identification of 3,6-dideoxy-3-(L-glyceroyl-amino)-D-glucose. a constituent of the antigenic polysaccharide of Eubacterium saburreum, strain V5

3,6-Dideoxy-3-(L-glyceroylamino)-D-glucose has been identified, for the first time, as a sugar component of the antigenic polysaccharide of Eubacterium saburreum strain V5, principally by n.m.r. and mass spectrometry.

Chemical structure of the polysaccharide antigen of Eubacterium saburreum, strain O2

The polysaccharide antigen produced by Eubacterium saburreum, strain O2, is composed of (1 leads to 6)-linked beta-D-glycero-D-galacto-heptopyranosyl residues, all of which are substituted with 6-deoxy-alpha-D-altro-heptofuranosyl groups at O-3.

Structural studies of the polysaccharide antigen of Eubacterium saburreum, strain 49

The polysaccharide antigen produced by Eubacterium saburreum, strain L 49, is composed of D-glycero-D-galacto-heptose and a new sugar, tentatively identified as 6-deoxy-D-altro-heptose. It contains chains of alternating (1 leads to 3)- and (1 leads to 6)- linked beta-D-glycero-D-galacto-heptopyranosyl residues, the latter being substituted with 6-deoxy-alpha-heptofuranosyl groups at O-3. The polysaccharide further contains 0-acetyl groups, linked to O-7 of part of the heptosyl residues and to O-2 of part of the 6-deoxyheptosyl groups.

Immunochemistry of a cell wall polysaccharide isolated from Eubacterium saburreum, strain L49

A polymer isolated from E. saburreum strain L49 contained O-acetylated glycero-galacto-heptose as the main constituent, and in addition an unknown aldose. The polymer was located at the outer part of the bacterial cell wall. The polymer reacted with antiserum to L49 microorganisms by precipitation and complement fixation. Two antigenic specificities were detected, one of which was destroyed by de-acetylation. The rabbit antibodies to both specificities were low-molecular-weight antibodies.