ShK – Stichodactyla toxin

ShK (Stichodactyla helianthus Neurotoxin) has been isolated from the venom of the Carribean sea anemone Stoichactis helianthus. ShK inhibits voltage-dependent potassium channels. It blocks Kv1.3 (KCNA3) potently and also Kv1.1 (KCNA1), Kv1.4 (KCNA4) and Kv1.6 (KCNA6) respectively with a Kd of 11 pM, 16 pM, 312 pM and 165 pM. Interestingly, it was also demonstrated that ShK potently inhibits the hKv3.2b channel with an IC50 value of approximately 0.6 nM