SNX-482. R-Type Ca2+�(Cav2.3) Channel Blocker.
SNX-482 is a peptidyl toxin originally isolated from venom of the spider Hysterocrates gigas Native SNX-482 blocks specifically Cav2.3 (a1E, R-type) channels in a voltage dependent manner. The block is reversible only upon application of strong voltage to facilitate unbinding. SNX-482 inhibits human Cav2.3 channels stably expressed in a mammalian cell line. An IC50 of 15-30 nM was obtained for block of Cav2.3 channel, using either patch clamp electrophysiology or K+-evoked Ca2+ flux. At low nanomolar concentrations, SNX-482 also blocked a native R-type Ca2+ current in rat neurohypophyseal nerve terminals, but concentrations of 200-500 nM had no effect on R-type Ca2+currents in several types of rat central neurons. SNX-482 was also used to demonstrate the contribution of Cav2. channels to transmitter release. Recently it was shown that higher concentrations of SNX-482 also block Cav2.1 channels in chromaffin cells.
Alomone Labs is pleased to offer SNX-482, a recombinant peptide expressed in and extracted from E. coli and purified to homogeneity.
Ion Channel Modulators; Voltage - Gated Ca2+ Channel Blockers.