Inhibits voltage-gated potassium channels (Kv1/KCNA) (PubMed:23895459). Is potent on Drosophila Shaker IR channels (IC(50)=94.25 nM), and rKv1.2/KCNA2 (IC(50)=172.59 nM), and moderately active on hKv1.3/KCNA3 (IC(50)=1006.48 nM), rKv1.6/KCNA6 (IC(50)=2245.93 nM), and Kv1.1/KCNA1 (IC(50) around 3 uM) (PubMed:23895459). In vivo, induces a rapid increase in swimming speed on zebrafish larvae, as well as death which occurs between 2 and 18 hours later (By similarity). Also paralyzes swimming crabs (C.danae) when injected at the junction between the body and the walking leg (PubMed:23895459). Contains 4 disulfide bonds. Has no activity on voltage-gated potassium channels rKv1.4/KCNA4, rKv1.5/KCNA5, rKv2.1/KCNB1, rKv3.1/KCNC1, rKv4.1/KCND1, rKv4.3/KCND3 channels, hERG/KCNH2, voltage-gated sodium channels rNav1.2/SCN2A, rNav1.4/SCN4A, and cockroach BgNav1.1. Belongs to the sea anemone type 5 potassium channel toxin family.