title: Use of synthetic peptides and site-specific antibodies to localize a diphtheria toxin sequence associated with ADP-ribosyltransferase activity.
abstract: Diphtheria toxin (DT) and Pseudomonas aeruginosa exotoxin A have the same molecular mechanism of toxicity; both toxins ADP-ribosylate a modified histidine residue in elongation factor 2. To help identify amino acids involved in this reaction, sequences in DT that share homology with P. aeruginosa exotoxin A were synthesized and examined for a role in the ADP-ribosyltransferase reaction. By using this approach, residues 32 to 54 of DT were found to define an epitope associated with antibody-mediated inhibition of DT enzyme activity. This lends further support to the notion that residues in this region of DT are involved in the enzymatic reaction.
authors.affiliation: Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston 29425.
authors.forename: J C
authors.initials: JC
authors.lastname: Olson
mesh_terms: D036002:ADP Ribose Transferases; D000595:Amino Acid Sequence; D000907:Antibodies, Bacterial / Q000276:immunology; D001427:Bacterial Toxins; D003353:Corynebacterium diphtheriae / Q000201:enzymology / Q000472:pathogenicity; D004167:Diphtheria Toxin / Q000737:chemistry* / Q000276:immunology; D005098:Exotoxins / Q000737:chemistry; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D011065:Poly(ADP-ribose) Polymerases / Q000737:chemistry* / Q000276:immunology; D011550:Pseudomonas aeruginosa / Q000201:enzymology / Q000472:pathogenicity; D013329:Structure-Activity Relationship; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A
chemical_list: D036002:ADP Ribose Transferases; D000907:Antibodies, Bacterial; D001427:Bacterial Toxins; D004167:Diphtheria Toxin; D005098:Exotoxins; D010455:Peptides; D011065:Poly(ADP-ribose) Polymerases; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A