title: A common antigenic determinant found in two functionally unrelated toxins.
abstract: The heat-stable enterotoxin ST Ib produced by enterotoxigenic E. coli strains shares a sequence homology with the sea snail neurotoxin, conotoxin GI. Rabbit antisera were raised against synthetic analogs of these toxins and to a six-residue peptide representing the region common to both toxins. Results from enzyme-linked immunosorbent assays indicate that the homologous region of both toxins represents part of their antigenic site. The lack of cross-reactivity exhibited by the six-residue common domain with serum directed against either toxin suggests that this region probably retains a similar conformation in the intact toxins but not in the isolated fragment.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000992:Antitoxins / Q000494:pharmacology; D001427:Bacterial Toxins; D020916:Conotoxins; D003429:Cross Reactions; D004768:Enterotoxins / Q000032:analysis* / Q000276:immunology / Q000633:toxicity; D000939:Epitopes / Q000032:analysis* / Q000276:immunology; D029968:Escherichia coli Proteins; D005260:Female; D051379:Mice; D008978:Mollusk Venoms / Q000032:analysis* / Q000276:immunology / Q000633:toxicity; D009123:Muscle Hypotonia / Q000209:etiology; D010243:Paralysis / Q000209:etiology; D011817:Rabbits; D012908:Snails
chemical_list: D000992:Antitoxins; D001427:Bacterial Toxins; D020916:Conotoxins; D004768:Enterotoxins; D000939:Epitopes; D029968:Escherichia coli Proteins; D008978:Mollusk Venoms; C034151:heat stable toxin (E coli); C029960:conotoxin GI