CLC-2-IN-AK42 (CLC-2 inhibitor AK42, AK42) is a potent, specific small-molecule inhibitor of voltage-gated chloride channel CLC-2 with IC50 of 17 nM (human CLC-2).AK42 displays unprecedented selectivity (>1,000-fold) over CLC-1, the closest CLC-2 homolog, and no off-target engagement a diverse panel of 61 CNS receptors, channels, and transporters expressed in brain tissue.AK-42 binds to an extracellular vestibule above the channel pore. AK-42 is almost three orders-of-magnitude more potent than MCFA, demonstrates high potency (IC50=14 nM for rat CLC-2) in manual patch-clamp experiments on CHO cells transiently transfected with rat CLC-2.AK-42 inhibits hyperpolarization-activated current in hippocampal cells, attenuates steady-state currents and eliminated relaxation currents in recorded neurons.AK-42 is a powerful tool for investigating CLC-2 neurophysiology.
