Overview
Synthetic peptide
- Salinas, M. et al. (2014) J. Biol. Chem. 289, 13363.
Alomone Labs Mambalgin-2 inhibits ASIC1a channels expressed in Xenopus oocytes.A. Representative time course of Mambalgin-2 (#STM-400) 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 partially inhibited by 200 nM Mambalgin-2 (top bar). B. Superimposed traces of ASIC1a currents upon application of control and of 200 nM Mambalgin-2 (taken from the recording in A).
Mambalgin-2 is a peptide toxin originally isolated from Dendroaspis polylepis (Black mamba) venom. It is a selective and potent ASIC1a blocker2. Mambalgins belong to the three-finger toxin family, albeit their limited structural similarity3. Molecular docking of mambalgin-2 is predicted to interact with the acidic binding pocket of ASIC1a2. Further mutagenesis studies in chimeric proteins uncovered the interactions of mambalgin-2 with β-ball and Palm regions of ASIC1a that are associated with a pH sensing property2.
Acid-sensing ion channels (ASICs) are proton-gated sodium channels1. They are abundant in the central as well as in the peripheral nervous systems and are sensitive to environmental pH1.
Environmental pH can change dramatically due to certain circumstances such as inflammatory condition as evident during epileptic seizures or tumor outgrowth3. In such cases, ASICs transform into their open conformation and import sodium ions, which then elicit neuronal action potential3.
