[1][2] Heteroscorpine (HS-1) is a component of the venom of the Thai giant scorpion Heterometrus laoticus.
The polypeptides of the Scorpine family possess two structural and functional domains: a N-terminal α-helix (which has a cytolytic and/or antimicrobial activity similar to that of insect defensins), and a C-terminal region with a CSαβ motif, which causes potassium channel-blocking activity.
[1][2] HS-1 is highly homologous in particular to the Scorpine toxin Panscorpine (from Emperor scorpion) and Opiscorpine (from Opistophthalmus carinatus), with an 80% similarity in amino acid sequence.
[3] Based on its sequence homology with other scorpine-like peptides, HS-1 is likely to be a voltage-gated potassium channel blocker.
Scanning electron microscopy shows that HS-1 causes roughening and blebbing of bacterial cell surfaces.