Stromatoxin-1 inhibits with high affinities Kv2.1 and Kv2.2, that encode delayed K+ channels (respectively, with IC50 of 12 and 21 nM). The block is voltage-dependent and slowly reversible. It is also a very sensitive inhibitor of Kv4.2, that encodes a transient K+ current (IC50 of 1.2 nM). Here also, the block is voltage-dependent indicating that ScTx-1 acts as a gating modifier rather than a pore blocker. Reversibility is faster on Kv4.2 channels. In contrast, ScTx-1 has no effect on Kv1.1, Kv1.2, Kv1.3, Kv1.4, Kv1.5, Kv1.6 or Kv3.4 channels.
- Applications:TARGET CLASS: Potassium channel; TARGET: Kv2; ACTION: Blocker
Peptides & proteins
AA SEQUENCE: Asp-Cys2-Thr-Arg-Met-Phe-Gly-Ala-Cys9-Arg-Arg-Asp-Ser-Asp-Cys15-Cys16-Pro-His-Leu-Gly-Cys21-Lys-Pro-Thr-Ser-Lys-Tyr-Cys28-Ala-Trp-Asp-Gly-Thr-Ile-NH2; DISULFIDE BONDS: Cys2-Cys16, Cys9-Cys21 and Cys15-Cys28; SOURCE: Synthetic; PURITY: > 98%