title: Characterization and partial purification from pheochromocytoma cells of an endogenous equivalent of scyllatoxin, a scorpion toxin which blocks small conductance Ca(2+)-activated K+ channels.
abstract: This work describes the partial purification of a heat-stable peptide which has the same properties as the scorpion toxin, scyllatoxin, a specific blocker of one class of Ca(2+)-activated K+ channels: (i) it competes with [125I]apamin for binding to the same site, (ii) like apamin and scyllatoxin, it blocks the after-potential hyperpolarization in skeletal muscle cells in culture, (iii) like apamin and scyllatoxin, it contracts guinea-pig taenia coli relaxed by epinephrine, (iv) it cross-reacts with antibodies raised against scyllatoxin but not with antibodies raised against apamin.
authors.affiliation: Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France.
authors.forename: P
authors.initials: P
authors.lastname: Auguste
authors.forename: M
authors.initials: M
authors.lastname: Hugues
authors.forename: M
authors.initials: M
authors.lastname: Borsotto
authors.forename: J
authors.initials: J
authors.lastname: Thibault
authors.forename: G
authors.initials: G
authors.lastname: Romey
authors.forename: T
authors.initials: T
authors.lastname: Coppola
authors.forename: M
authors.initials: M
authors.lastname: Lazdunski
mesh_terms: D000818:Animals; D000918:Antibody Specificity / Q000276:immunology; D001030:Apamin / Q000037:antagonists & inhibitors / Q000378:metabolism; D001667:Binding, Competitive / Q000502:physiology; D002118:Calcium / Q000502:physiology*; D004553:Electric Conductivity; D010450:Endopeptidases; D006358:Hot Temperature; D016716:PC12 Cells; D015221:Potassium Channels / Q000187:drug effects*; D011863:Radioimmunoassay; D017981:Receptors, Neurotransmitter / Q000378:metabolism; D012604:Scorpion Venoms / Q000276:immunology / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D015221:Potassium Channels; D017981:Receptors, Neurotransmitter; D012604:Scorpion Venoms; C033799:apamin receptor; C056574:leiurotoxin I; D001030:Apamin; D010450:Endopeptidases; D002118:Calcium