Potassium channel toxin kappa-KTx 5.1

UniProtKB accession:  P0DJ41

Grouped By:  Matching UniProtKB accession

UniProtKB description:  Weak blocker of potassium channels Kv1.1/KCNA1 (IC(50)=578.5 nM-9.9 uM) and Kv1.6/KCNA6 (~60% block at 30 uM of toxin) (PubMed:22305749, PubMed:26724500). Acts by binding to the pore and occluding it (PubMed:22305749). Has a voltage-dependent mode of action, which can be explained by a high content of basic residues causing repulsions at higher membrane voltages (PubMed:22305749). Shows a weak interaction with muscle-type nicotinic acetylcholine receptors (nAChR), since it inhibits alpha-bungarotoxin binding to muscle-type nAChR from T.californica (IC(50)=1.4 uM) (PubMed:31276191). This suggests it probably weakly inhibits muscle nAChR (PubMed:31276191). The mode of binding to potassium channels of this toxin differs from its homologs (including HefuTx1), since it lacks the key aromatic residue of the functional dyad. In contrast, its functionally important site is composed of a number of basic residues (PubMed:32172732).