A novel toxin from the venom of the scorpion Tityus trivittatus, is the first member of a new alpha-KTX subfamily.
The first example of a new sub-family of toxins (alpha-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 alpha/beta scaffold with a pI value of 8.98. The sequence identities with all the other known alpha-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).
Abdel-Mottaleb
Yousra
Y
Laboratory of Toxicology, University of Leuven, Onderwijs and Navorsing II, Herestraat 49, Postbus 922, 3000 Leuven, Belgium.
Coronas
Fredy V
FV
de Roodt
Adolfo R
AR
Possani
Lourival D
LD
Tytgat
Jan
J
D000595:Amino Acid Sequence; D000818:Animals; D008969:Molecular Sequence Data; D026902:Potassium Channel Blockers / Q000737:chemistry / Q000378:metabolism; D015221:Potassium Channels / Q000378:metabolism; D012604:Scorpion Venoms / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D012605:Scorpions / Q000737:chemistry*; D016415:Sequence Alignment
D026902:Potassium Channel Blockers; D015221:Potassium Channels; D012604:Scorpion Venoms; C508779:alpha-KTx20.1 protein, Tityus trivittatus