title: Biochemical and electrophysiological characterization of two sea anemone type 1 potassium toxins from a geographically distant population of Bunodosoma caissarum.
abstract: Sea anemone (Cnidaria, Anthozoa) venom is an important source of bioactive compounds used as tools to study the pharmacology and structure-function of voltage-gated K+ channels (KV). These neurotoxins can be divided into four different types, according to their structure and mode of action. In this work, for the first time, two toxins were purified from the venom of Bunodosoma caissarum population from Saint Peter and Saint Paul Archipelago, Brazil. Sequence alignment and phylogenetic analysis reveals that BcsTx1 and BcsTx2 are the newest members of the sea anemone type 1 potassium channel toxins. Their functional characterization was performed by means of a wide electrophysiological screening on 12 different subtypes of KV channels (KV1.1-KV1.6; KV2.1; KV3.1; KV4.2; KV4.3; hERG and Shaker IR). BcsTx1 shows a high affinity for rKv1.2 over rKv1.6, hKv1.3, Shaker IR and rKv1.1, while Bcstx2 potently blocked rKv1.6 over hKv1.3, rKv1.1, Shaker IR and rKv1.2. Furthermore, we also report for the first time a venom composition and biological activity comparison between two geographically distant populations of sea anemones.
authors: Department of Physiology, Institute of Biosciences, University of São Paulo, São Paulo, SP, 05508-090, Brazil. zaharenko@usp.br
authors: Diego J B
authors: DJ
authors: Orts
authors: Steve
authors: S
authors: Peigneur
authors: Bruno
authors: B
authors: Madio
authors: Juliana S
authors: JS
authors: Cassoli
authors: Gabriela G
authors: GG
authors: Montandon
authors: Adriano M C
authors: AM
authors: Pimenta
authors: José E P W
authors: JE
authors: Bicudo
authors: José C
authors: JC
authors: Freitas
authors: André J
authors: AJ
authors: Zaharenko
authors: Jan
authors: J
authors: Tytgat
mesh_terms: D000818:Animals; D001938:Brazil; D003064:Cnidarian Venoms / Q000737:chemistry / Q000494:pharmacology*; D055724:Electrophysiological Phenomena; D006801:Humans; D010802:Phylogeny; D026902:Potassium Channel Blockers / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D024642:Potassium Channels, Voltage-Gated / Q000037:antagonists & inhibitors*; D051381:Rats; D012615:Sea Anemones / Q000737:chemistry*; D016415:Sequence Alignment
chemical_list: D003064:Cnidarian Venoms; D026902:Potassium Channel Blockers; D024642:Potassium Channels, Voltage-Gated