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A novel toxin from the venom of the scorpion Tityus trivittatus , is the first member of a new α‐KTX subfamily
Author(s) -
Abdel-Mottaleb Yousra,
Coronas Fredy V.,
de Roodt Adolfo R.,
Possani Lourival D.,
Tytgat Jan
Publication year - 2006
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2005.12.073
Subject(s) - scorpion toxin , scorpion , scorpion venoms , venom , herg , cysteine , edman degradation , toxin , subfamily , chemistry , biology , peptide sequence , genetics , stereochemistry , biochemistry , biophysics , gene , potassium channel , enzyme
The first example of a new sub‐family of toxins (α‐KTx20.1) from the scorpion Tityus trivittatus was purified, sequenced and characterized physiologically. It has 29 amino acid residues, three disulfide bridges assumed to adopt the cysteine‐stabilized α/β scaffold with a p I value of 8.98. The sequence identities with all the other known α‐KTx are less than 40%. Its effects were verified using seven different cloned K + channels (vertebrate Kv1.1–1.5, Shaker IR and hERG) expressed in Xenopus leavis oocytes. The toxin‐induced effects show large differences among the different K + channels and a preference towards Kv1.3 (EC50 = 7.9 ± 1.4 nM).