title: Antigenic polymorphism of the "short" scorpion toxins able to block K+ channels.
abstract: BmTX3 is a toxin recently characterised from the venom of the Chinese scorpion Buthus martensi Karch, which specifically blocks a transient A-type K+ current in striatum neurons in culture and binds to rat brain synaptosomes with high affinity. With Aa1 and AmmTX3, it belongs to the new alpha-KTx15 subfamily from "short-chain" scorpion toxins, which specifically block different types of K+ channels. Here, a highly specific polyclonal antiserum was raised in rabbit against a C-terminal deleted BmTX3 analogue (BmTX-del YP). Using liquid-phase radioimmunoassay, we have studied its selectivity for the toxins from the alpha-KTx15 subfamily. We have also demonstrated that no/or poor cross-reactivity was observed with a panel of "short-chain" scorpion toxins representative of other structurally different subfamilies. These results suggest that a wide antigenic polymorphism, similar to that previously observed for "long-chain" scorpion toxins acting as modulators of voltage-activated Na+ channels, is also the rule for the "short-chain" scorpion toxins able to block K+ channels.
authors.affiliation: CNRS FRE 2738, Laboratoire de Biochimie, Institut Jean Roche, Faculté de Médecine Nord, Université de la Méditerranée, Boulevard Pierre Dramard, 13916 Marseille cedex 20, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Vacher
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Martin-Eauclaire
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001667:Binding, Competitive; D018999:Charybdotoxin / Q000235:genetics; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D014644:Genetic Variation; D007106:Immune Sera / Q000276:immunology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011863:Radioimmunoassay; D012604:Scorpion Venoms / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D012605:Scorpions; D016415:Sequence Alignment; D017385:Sequence Homology
chemical_list: D007106:Immune Sera; D012604:Scorpion Venoms; C418406:TX3 toxin, Buthus martensii; D018999:Charybdotoxin