U-shaped dose-dependent effects of BmK AS, a unique scorpion polypeptide toxin, on voltage-gated sodium channels.

ABSTRACT:

Background and purpose

Buthus martensi Karsch (BmK) AS is a scorpion polypeptide toxin, said to target the voltage-gated sodium channels (VGSCs). However, the mechanism of action of BmK AS on the VGSCs has yet to be defined.

Experimental approach

We examined the electrophysiological effects of BmK AS in a wide dose range on the rat brain-type VGSC alpha-subunit, rNav1.2a, heterologously expressed in Xenopus oocytes and on the VGSCs endogenously expressed in the dorsal root ganglion neuroblastoma ND7-23 cell line.

Key results

In the oocytes, BmK AS depolarized the voltage dependence of activation and inactivation of rNav1.2a at 0.1 and 500 nM whereas these parameters were hyperpolarized at 1 nM. In ND7-23 cells, BmK AS hyperpolarized the voltage dependence of activatio

SUBMITTER: Zhu MM 

PROVIDER: S-EPMC2807651 | biostudies-literature | 2009 Dec

REPOSITORIES: biostudies-literature