title: Characterization of a potassium channel toxin from the Caribbean Sea anemone Stichodactyla helianthus.
abstract: A peptide toxin, ShK, that blocks voltage-dependent potassium channels was isolated from the whole body extract of the Caribbean sea anemone Stichodactyla helianthus. It competes with dendrotoxin I and alpha-dendrotoxin for binding to synaptosomal membranes of rat brain, facilities acetylcholine release at an avian neuromuscular junction and suppresses K+ currents in rat dorsal root ganglion neurones in culture. Its amino acid sequence is R1SCIDTIPKS10RCTAFQCKHS20MKYRLSFCRK30TCGTC35. There is no homology with other K+ channel-blocking peptides, except for BgK from the sea anemone Bunodosoma granulifera. ShK and BgK appear to be in a different structural class from other toxins affecting K+ channels.
authors.affiliation: Facultad de Biología, Universidad de La Habana, Cuba.
authors.forename: O
authors.initials: O
authors.lastname: Castañeda
authors.forename: V
authors.initials: V
authors.lastname: Sotolongo
authors.forename: A M
authors.initials: AM
authors.lastname: Amor
authors.forename: R
authors.initials: R
authors.lastname: Stöcklin
authors.forename: A J
authors.initials: AJ
authors.lastname: Anderson
authors.forename: A L
authors.initials: AL
authors.lastname: Harvey
authors.forename: A
authors.initials: A
authors.lastname: Engström
authors.forename: C
authors.initials: C
authors.lastname: Wernstedt
authors.forename: E
authors.initials: E
authors.lastname: Karlsson
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D003064:Cnidarian Venoms / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity; D008969:Molecular Sequence Data; D026902:Potassium Channel Blockers; D015221:Potassium Channels / Q000032:analysis; D051381:Rats; D012615:Sea Anemones / Q000737:chemistry*; D013574:Synaptosomes / Q000378:metabolism
chemical_list: D000596:Amino Acids; D003064:Cnidarian Venoms; D026902:Potassium Channel Blockers; D015221:Potassium Channels; C095391:ShK neurotoxin