Electrophysiological characterization of BmK M1, an alpha-like toxin from Buthus martensi Karsch venom

  • FEBS Lett. 2001 Apr 20;495(1-2):61-5. doi: 10.1016/s0014-5793(01)02365-1.
C Goudet  1 ,  I Huys ,  E Clynen ,  L Schoofs ,  D C Wang ,  E Waelkens ,  J Tytgat
Affiliations
  • 1. Laboratory of Toxicology, University of Leuven, E. Van Evenstraat 4, B-3000 Leuven, Belgium.
PMID: 11322948 DOI: 10.1016/s0014-5793(01)02365-1
Abstract

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.

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