Biomaterial Database

Characterization of toxins A and B of Clostridium difficile with monoclonal antibodies. 1986

D M Lyerly, and C J Phelps, and J Toth, and T D Wilkins

Two monoclonal antibodies (MAbs) were used to learn more about the structures of Clostridium difficile toxins A and B. One of the antibodies, the PCG-4 MAb, reacted specifically with toxin A. This MAb precipitated toxin A and neutralized the enterotoxic but not the cytotoxic activity of the toxin. The site to which the antibody bound was resistant to denaturation with sodium dodecyl sulfate; however, it was destroyed by N-bromosuccinimide. Immunoblot analysis with the PCG-4 MAb revealed the presence of a large number of bands in preparations of denatured toxin A, suggesting that toxin A exists as an aggregate of smaller components. The antibody was covalently coupled to Affi-Gel 10, and the gel was used to purify toxin A from the culture filtrate of a highly toxigenic strain of C. difficile by immunoaffinity chromatography. The second antibody, the G-2 MAb, cross-reacted with toxins A and B. The cross-reaction was confirmed by immunoblot analysis. These results show that toxins A and B share an epitope and suggest that they have a common subunit. The G-2 MAb did not neutralize or precipitate either toxin. The site to which the G-2 MAb bound was partially destroyed by sodium dodecyl sulfate and was resistant to oxidation with N-bromosuccinimide.

UI	MeSH Term	Description	Entries
D007163	Immunosorbent Techniques	Techniques for removal by adsorption and subsequent elution of a specific antibody or antigen using an immunosorbent containing the homologous antigen or antibody.	Immunoadsorbent Techniques,Immunoadsorbent Technics,Immunosorbent Technics,Immunoadsorbent Technic,Immunoadsorbent Technique,Immunosorbent Technic,Immunosorbent Technique,Technic, Immunoadsorbent,Technic, Immunosorbent,Technics, Immunoadsorbent,Technics, Immunosorbent,Technique, Immunoadsorbent,Technique, Immunosorbent,Techniques, Immunoadsorbent,Techniques, Immunosorbent
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D009500	Neutralization Tests	The measurement of infection-blocking titer of ANTISERA by testing a series of dilutions for a given virus-antiserum interaction end-point, which is generally the dilution at which tissue cultures inoculated with the serum-virus mixtures demonstrate cytopathology (CPE) or the dilution at which 50% of test animals injected with serum-virus mixtures show infectivity (ID50) or die (LD50).	Neutralization Test,Test, Neutralization,Tests, Neutralization
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D002846	Chromatography, Affinity	A chromatographic technique that utilizes the ability of biological molecules, often ANTIBODIES, to bind to certain ligands specifically and reversibly. It is used in protein biochemistry. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Chromatography, Bioaffinity,Immunochromatography,Affinity Chromatography,Bioaffinity Chromatography
D003013	Clostridium	A genus of motile or nonmotile gram-positive bacteria of the family Clostridiaceae. Many species have been identified with some being pathogenic. They occur in water, soil, and in the intestinal tract of humans and lower animals.
D004768	Enterotoxins	Substances that are toxic to the intestinal tract causing vomiting, diarrhea, etc.; most common enterotoxins are produced by bacteria.	Staphylococcal Enterotoxin,Enterotoxin,Staphylococcal Enterotoxins,Enterotoxin, Staphylococcal,Enterotoxins, Staphylococcal
D000911	Antibodies, Monoclonal	Antibodies produced by a single clone of cells.	Monoclonal Antibodies,Monoclonal Antibody,Antibody, Monoclonal
D000918	Antibody Specificity	The property of antibodies which enables them to react with some ANTIGENIC DETERMINANTS and not with others. Specificity is dependent on chemical composition, physical forces, and molecular structure at the binding site.	Antibody Specificities,Specificities, Antibody,Specificity, Antibody
D000939	Epitopes	Sites on an antigen that interact with specific antibodies.	Antigenic Determinant,Antigenic Determinants,Antigenic Specificity,Epitope,Determinant, Antigenic,Determinants, Antigenic,Specificity, Antigenic