Modulation of BmK AS, a scorpion neurotoxic polypeptide, on voltage-gated Na+ channels in B104 neuronal cell line.

Abstract The modulation of BmK AS, a neurotoxic polypeptide from scorpion Buthus martensi Karsch, on the voltage-gated Na + channels has been investigated in the B104 neuroblastoma cell line by whole-cell patch clamping. It was found that the whole Na + currents and tetrodotoxin-resistant Na + current were depressed in a biphasic manner and both steady-state activation and inactivation curves were shifted toward the hyperpolarizing direction in the presence of BmK AS. The results suggested that BmK AS could inhibit both tetrodotoxin-sensitive and -resistant Na + currents via modulating the gating mechanism of the voltage-gated Na + channels in B104 cells.