Premium
Bcs T x3 is a founder of a novel sea anemone toxin family of potassium channel blocker
Author(s) -
Orts Diego J. B.,
Moran Yehu,
Cologna Camila T.,
Peigneur Steve,
Madio Bruno,
Praher Daniela,
Quinton Loic,
Pauw Edwin,
Bicudo José E. P. W.,
Tytgat Jan,
Freitas José C.
Publication year - 2013
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/febs.12456
Subject(s) - sea anemone , xenopus , scorpion toxin , toxin , potassium channel , biology , potassium channel blocker , tetrodotoxin , peptide sequence , venom , peptide , ion channel , shaker , population , microbiology and biotechnology , biochemistry , biophysics , receptor , botany , medicine , gene , scorpion , physics , vibration , environmental health , quantum mechanics
Sea anemone venoms have become a rich source of peptide toxins which are invaluable tools for studying the structure and functions of ion channels. In this work, BcsTx3, a toxin found in the venom of a B unodosoma caissarum (population captured at the S aint P eter and S aint P aul A rchipelago, B razil) was purified and biochemically and pharmacologically characterized. The pharmacological effects were studied on 12 different subtypes of voltage‐gated potassium channels (K V 1.1–K V 1.6; K V 2.1; K V 3.1; K V 4.2; K V 4.3; h ERG and Shaker IR) and three cloned voltage‐gated sodium channel isoforms (Na V 1.2, Na V 1.4 and BgNa V 1.1) expressed in X enopus laevis oocytes. BcsTx3 shows a high affinity for D rosophila S haker IR channels over rKv1.2, hKv1.3 and rKv1.6, and is not active on Na V channels. Biochemical characterization reveals that BcsTx3 is a 50 amino acid peptide crosslinked by four disulfide bridges, and sequence comparison allowed BcsTx3 to be classified as a novel type of sea anemone toxin acting on K V channels. Moreover, putative toxins homologous to BcsTx3 from two additional actiniarian species suggest an ancient origin of this newly discovered toxin family.