What is "parabutoxin"

Parabutoxin (PBTx) is a Shaker-related voltage-gated K channel (Kvα1) inhibitor purified from different Parabuthus scorpion species found in southern Africa. It occurs in different forms: parabutoxin 1 (PBTx1), parabutoxin 2 (PBTx2), parabutoxin 3 (PBTx3) and parabutoxin (PBTx10). The different variants have different affinities towards Kvα1 channels.