PubMed Health⌕ Search

Biomedical subjects

E Katzenellenbogen

Publications and source records attributed to E Katzenellenbogen.

47 records · Page 3Linked to original sources
PubMed1981

Serological analysis of core oligosaccharides of Shigella flexneri serotype 6 and its R mutants lipopolysaccharides.

The core oligosaccharides originating from Shigella flexneri 6 S strains and R mutants were examined by the complement fixation inhibition and passive hemolysis inhibition tests using antisera against the complete and partially degraded core regions. Strong cross reactivity between Shigella flexneri 6, Shigella sonnei phase II and E. coli C core fractions which all are of R1 type was observed. Terminal beta-D-glucosyl groups and alpha-D-galactosyl-1,2-alpha-D-galactosyl sequences are essential elements of R1 type immunodeterminants. Heptose region of the R1 cores seems not be involved in their serological specificity.

Antigens, Bacterial↗
PubMed1980

Structural studies on Shigella flexneri serotype 6 core region.

The core structure of Shigella flexneri serotype 6 has been investigated. The methods used in these studies involved methylation analysis, periodate oxidation, Smith degradation and enzymic modifications of core oligosaccharides isolated from two smooth strains and four rough mutants. As a result the complete core region was established (Formula: see text) where DGalp = D-galactopyranose, DGlcp = D-glucopyranose, L alpha DHepp = L-glycero-D-mannoheptapyranose, dOclA = 3-deoxy-D-manno-octulosonic, DGlcNp = 2-amino-2-deoxy-D-glucopyranose and P--PEtN = pyrophosphorylethanolamine (partially substituted). In the R mutants examined two types of mutation have been observed: (1) defect in heptose region (lack of D-glucosamine) or (2) defects in hexose region of the core.

Carbohydrate Sequence↗
PubMed1978

Structural studies of Shigella flexneri O-antigens.

The structures of the O-antigens of all known serotypes and subserotypes of Shigella flexneri have been reinvestigated. The results support the assumption that these antigens are composed of a basic tetrasaccharide repeating unit (1), to which alpha-D-glucopyranosyl and/or O-acetyl groups are attached at different positions. Leads to 3)-beta-D-GlcNAcp-(1 leads to 2)-alpha-L-Rhap-(1 leads to 2)-alpha-L-Rhap-(1 leads to 3)-alpha-L-Rhap-(1 leads to The immunological determinants responsible for O-factors I, II, IV, V and 7, 8 contain alpha-D-gluco-pyranosyl groups, the locations of which have been determined. O-Factor 6 is due to O-acetyl groups, linked to O-2 of the 3-substituted alpha-L-rhamnopyranosyl residue in unit 1 and O-factor III seems to be due to the same groups. The chemical natures of the determinants responsible for O-factors 4 and 3, 4 are still obscure. The structural studies indicate that the immunological classification of Sh. flexneri serotypes and subserotypes, as regards these O-factors, may need revision.

Carbohydrates↗
PubMed1978

Immunochemical characteristics of Shigella sonnei and serotype 6 Shigella flexneri lipopolysaccharides and enterobacterial common antigen.

Immunochemical studies on Shigella sonnei and serotype 6 Shigella flexneri 0 antigens (lipopolysaccharides) and enterobacterial common antigen (ECA) isolated from Shigella sonnei were carried out. Oligosaccharide structure of 0-specific chain of serotype 6 Shigella fiexneri lipopolysaccharide was defined and beta-L-rhamnosyl-1,3-N-acetyl-D-galactosamin as immunodeterminant of type VI specificity was recognized. The structures of core regions of lipopolysaccharides isolated from R mutants of both Shigella subgroups were established. On the base of the serological and structural results it has been suggested that these core regions are identical and very close to RI core structure of E. coli C. The effective method of isolation and purification of enterobacterial common antigen from Shigella sonnei was elaborated and its immunological properties as well as chemical character defined.

Antigens, Bacterial↗
PubMed1977

Structural studies of the Shigella flexneri variant X, type 5 a and type 5 b O-antigens.

Previous studies of different Shigella flexneri O-antigens indicate that their O-specific region is composed of oligosaccharide repeating units containing a basic tetrasaccharide structure, to which alpha-D-glucopyranosyl groups and O-acetyl groups may be attached to different positions. Structural studies of O-antigens from variant X, type 5a and type 5b lend further support to this assumption. These antigens contain terminal alpha-D-glucopyranosyl groups, one each per repeating unit in X and 5a, two in 5b. The location of these groups in the repeating unit has been determined.

Carbohydrates↗
PubMed1975

Immunochemical studies on the serotype of Shigella flexneri and its recombinant.

Chemical and serologic analysis of polysaccharides of Shigella flexneri 2b and its recombinant revealed complete defect of the gene responsible for type II specificity as a result of recombination. At the same time, function of the gene in the same locus responsible for 7,8 group specificity was partially inhibited. Attenuation of group antigen 7,8, associated with partial uncovering of the structure of the basic chain, causes appearance of a distinct 3,4 group antigen. Changes of this type in Shigella flexneri have not been described hitherto.

Conjugation, Genetic↗