A new Kaliotoxin selective towards Kv1.3 and Kv1.2 but not Kv1.1 channels expressed in oocytes.
In this paper were described the purification, the sequencing, and the immunological and biological characterization of a new Kaliotoxin analog, Aam-KTX, from the venom of the scorpion Androctonus amoreuxi. The toxin effects on three cloned Kv channels (Kv1.1, Kv1.2, and Kv1.3) were investigated in Xenopus oocytes using electrophysiology experiments. The Aam-KTX preference for Kv1.3 channel versus Kv1.2 was expected (EC(50) values, 1.1+/-0.02 and 10.4+/-1.5 nM, respectively) but its total inefficacy on Kv1.1 was very surprising. 3D molecular modeling of Aam-KTX brought putative answers to this difference in selectivity.
Abbas
Najwa
N
CNRS UMR 6231, CRN2M, Université de la Méditerranée et Université Paul Cézanne, 51, Bd Pierre Dramard, 13916 Marseilles, France.
Belghazi
Maya
M
Abdel-Mottaleb
Yousra
Y
Tytgat
Jan
J
Bougis
Pierre E
PE
Martin-Eauclaire
Marie-France
MF
D000595:Amino Acid Sequence; D000818:Animals; D051662:Kv1.1 Potassium Channel / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D051663:Kv1.2 Potassium Channel / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D051664:Kv1.3 Potassium Channel / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism; D026902:Potassium Channel Blockers / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D011487:Protein Conformation; D051381:Rats; D012604:Scorpion Venoms / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology*; D012605:Scorpions / Q000737:chemistry; D014982:Xenopus laevis
C489293:Kcna1 protein, rat; D051663:Kv1.2 Potassium Channel; D051664:Kv1.3 Potassium Channel; D026902:Potassium Channel Blockers; D012604:Scorpion Venoms; C072276:kaliotoxin; D051662:Kv1.1 Potassium Channel