Overview
- Diochot, S. et al. (2012) Nature 490, 552.
- Baron, A. et al. (2013) Toxicon doi: 10.1016/j.toxicon.2013.04.008.
Alomone Labs Mambalgin-3 blocks Asic1a channels expressed in Xenopus oocytes.A. Representative time course of Mambalgin-3 (#STM-500) inhibition of Asic1a currents. Membrane potential was held at -80 mV, current was elicited every 50 sec by transient application of pH 5.5, and significantly inhibited by 200 nM Mambalgin-3 (top bar, green). B. Superimposed traces of Asic1a currents upon perfusion of control (black) and of 200 nM Mambalgin-3 (green), taken from the recording in A.
Mambalgin-3 is a peptide toxin originally isolated from the green mamba (Dendroaspis augusticeps) snake venom1. The toxin inhibits rat ASIC1a (IC50 = 17 nM), ASIC1b (IC50 = 44 nM) and heteromeric ASIC1a-ASIC2a (IC50 = 252 nM) channels1.
Acid-sensing ion channels (ASICs) are voltage-independent proton-gated cation channels that are largely expressed in the nervous system as well as in some non-neuronal tissues. In rodents, six different isoforms (ASIC1a, 1b, 2a, 2b, 3 and 4) can associate into homo- or hetero-trimers to form a functional channel1.
Mambalgins define a new structural and functional class among snake three-finger toxins. These type of toxins are found in snake venoms (Mambalgin1 and 2 were originally isolated from black mambas) and are characterized by their distinctive structure2. Mambalgins are the only three-finger toxins to target ASIC channels and show no neurotoxic effect. These three-finger toxins show an analgesic effect against acute and inflammatory pain upon central and peripheral injection that can be as strong as morphine. Mambalgins cause much less tolerance than morphine and no respiratory distress3.
