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Functional properties of the carboxy-terminal host cell-binding domains of the two toxins, TcdA and TcdB, expressed by Clostridium difficile
- Source :
- Glycobiology. 18:698-706
- Publication Year :
- 2008
- Publisher :
- Oxford University Press (OUP), 2008.
-
Abstract
- The biological and ligand-binding properties of recombinant C-terminal cell-binding domains (CBDs) and subdomains of the two large exotoxins, Toxin A (TcdA) and Toxin B (TcdB) expressed by Clostridium difficile were examined in the hemagglutination and Verocytotoxicity neutralization assays and by qualitative affinity chromatography using Sepharose-linked alpha Gal(1,3)betaGal(1,4)beta Glc as well as the direct electrospray ionization mass spectrometry (ES-MS) assay. These studies revealed that, whereas the full-length TcdA CBD agglutinated rabbit erythrocytes, neutralized TcdA-mediated Vero cell death and bound to alpha Gal(1,3)betaGal(1,4)beta Glc-derivatized Sepharose, the TcdB CBD was inactive in these functional assays. Moreover, retention by alpha Gal(1,3)betaGal(1,4)beta Glc-derivatized Sepharose corresponded to the number of available TcdA subdomain ligand-binding sites. By contrast, the ES-MS assays revealed that both the TcdA and TcdB CBD bind to 8-methoxycarbonyloctyl-alpha Gal(1,3)betaGal(1,4)beta Glc sequences with similar avidities. Additional ES-MS experiments using chemically altered alpha Gal(1,3)betaGal(1,4)beta Glc sequences also revealed that the TcdA and TcdB CBD will tolerate a fair amount of structural variation in their complementary glycan ligands. Although the studies are consistent with the known ligand-binding properties of the TcdA and TcdB holotoxins, they also revealed subtle heretofore unrecognized functional differences in their receptor recognition properties.
- Subjects :
- Models, Molecular
Glycan
Hemagglutination
Bacterial Toxins
Clostridium difficile toxin A
Clostridium difficile toxin B
Models, Biological
Biochemistry
law.invention
Sepharose
Enterotoxins
Bacterial Proteins
Affinity chromatography
law
Chlorocebus aethiops
Toxicity Tests
Animals
Vero Cells
biology
Clostridioides difficile
Molecular biology
Peptide Fragments
Protein Structure, Tertiary
Host-Pathogen Interactions
Vero cell
biology.protein
Recombinant DNA
Protein Binding
Subjects
Details
- ISSN :
- 14602423 and 09596658
- Volume :
- 18
- Database :
- OpenAIRE
- Journal :
- Glycobiology
- Accession number :
- edsair.doi.dedup.....6bae2947de5ae9faf28937a2149b6e31