MitTx-alpha is a subunit of MitTx. MitTx is a potent, persistent, and selective agonist for acid-sensing ion channels (ASICs). MitTx is highly selective for the ASIC1 subtype at neutral pH; under more acidic conditions (pH<6.5), MitTx massively potentiates (>100-fold) proton-evoked activation of ASIC2a channels.