rw-Agatoxin IVA A Blocker of P/Q-Type Cav Channels

rw-Agatoxin IVA

A Blocker of P/Q-Type Ca_v Channels

Cav2.1 currents were elicited by 40 ms voltage ramp from a holding potential of -100 mV to +60 mV, applied every 10 sec using whole-cell voltage clamp technique. Left: Superimposed traces of Cav2.1 currents under control conditions (black) and following 2 min perfusion with 200 nM rw-Agatoxin IVA (#RTA-500), (red). Right: Time course of Cav2.1 peak current amplitude change as a result of the application of 200 nM rw-Agatoxin IVA (duration of perfusion indicated by horizontal bar).

Native w-Agatoxin IVA was originally isolated from Agelenopsis aperta spider venom, and was shown to be a selective blocker of Ca_v2.1 (P/Q type) channels¹. However, the sensitivity depends on the auxiliary b subunit isoform² and on the splice variant³. Therefore, the effective concentration varies between systems. In accordance, the toxin blocks presynaptic Ca²⁺ currents and synaptic transmission in a variety of synapses^4,5.

w-Agatoxin IVA is widely used in electrophysiological measurements of cloned and native channels^6,7. It is used to assess the role of Ca_v2.1 channels in synaptic transmission⁴. In addition it was used to map the spatial distribution of Ca_v2.1 channels in mouse cerebellar and hippocampal brain slices⁸.

Alomone Labs is pleased to offer rw-Agatoxin IVA , a recombinant protein expressed and purified from E. coli.