SHK

ShK toxin blocks voltage-dependent potassium channel (Kv1.3 channel). ShK toxin can be isolated from the whole body extract of the Caribbean sea anemone (Stichodactylu helianthus). ShK toxin competes with dendrotoxin I and α-dendrotoxin for binding to synaptosomal membranes of rat brain, facilitates acetylcholine release. ShK toxin suppresses K+ currents in cultured rat dorsal root ganglion neurons. ShK toxin also inhibits T lymphocyte proliferation[1][2].

[1] Castaeda O, et al. Characterization of a potassium channel toxin from the Caribbean Sea anemone Stichodactyla helianthus. Toxicon. 1995 May;33(5):603-13. DOI:10.1016/0041-0101(95)00013-c
[2] Beeton C, et al. The D-diastereomer of ShK toxin selectively blocks voltage-gated K+ channels and inhibits T lymphocyte proliferation. J Biol Chem. 2008 Jan 11;283(2):988-97. DOI:10.1074/jbc.M706008200