Electrophysiological characterization of BmK M1, an alpha-like toxin from Buthus martensi Karsch venom.
The present study investigates the electrophysiological actions of BmK M1, an alpha-like toxin purified from the venom of the scorpion Buthus martensi Karsch, on voltage-gated Na+ channels. Using the voltage clamp technique, we assessed the BmK M1 activity on the cardiac Na+ channel (hH1) functionally expressed in Xenopus oocytes. The main actions of the toxin are a concentration-dependent slowing of the inactivation process and a hyperpolarizing shift of the steady-state inactivation. This work is the first electrophysiological characterization of BmK M1 on a cloned Na+ channel, demonstrating that this toxin belongs to the class of scorpion alpha-toxins. Our results also show that BmK M1 can be considered as a cardiotoxin.
Goudet
C
C
Laboratory of Toxicology, University of Leuven, E. Van Evenstraat 4, B-3000 Leuven, Belgium.
Huys
I
I
Clynen
E
E
Schoofs
L
L
Wang
D C
DC
Waelkens
E
E
Tytgat
J
J
D000818:Animals; D004305:Dose-Response Relationship, Drug; D015870:Gene Expression; D006801:Humans; D019476:Insect Proteins; D008564:Membrane Potentials / Q000187:drug effects; D008845:Microinjections; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000494:pharmacology; D009865:Oocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D018408:Patch-Clamp Techniques; D018075:RNA, Complementary / Q000008:administration & dosage / Q000235:genetics / Q000378:metabolism; D012604:Scorpion Venoms / Q000494:pharmacology*; D012605:Scorpions; D017386:Sequence Homology, Amino Acid; D026941:Sodium Channel Blockers; D015222:Sodium Channels / Q000235:genetics / Q000378:metabolism; D014981:Xenopus
C403888:BmK M1 neurotoxin; D019476:Insect Proteins; D009498:Neurotoxins; D018075:RNA, Complementary; D012604:Scorpion Venoms; D026941:Sodium Channel Blockers; D015222:Sodium Channels