a small, basic, polypeptidic toxin which blocks a class of Ca²⁺-activated K⁺ channels; crosses the blood brain barrier; possesses a convulsant activity.

18-amino acid peptide with 2 disulfide bridges, from Apis mellifera bee venom.

• Molecular Weight : 2,027 Da.
  
  
• Solubility in : well in water and saline.
  
  
• Purity min. : 95% (HPLC).
  
  
• Biological Activity : nanomolar concentrations block small conductance Ca²⁺-activated K⁺ channels. Induces motor hyperactivity and is a potent convulsant.
  
  
• Toxicity (LD₅₀) : mice (i.v.): 3.8 mg/kg.
  
  
• Storage recommendations : Store at -4°C.
  
  
• CAS Reg. No. : 24345-16-2
  
  
• Merck Index 11th Ed. : 757
  
  
• Bibliography :
  
  1. Moczydlowski et al. "An emerging pharmacology of peptide toxins targeted against potassium channels." J. Membr. Biol. (1988). 105(2):95
  2. Bernardi et al. "Molecular properties of potassium channels." Arzneim.-Forsch./Drug Res. (1989). 39(1), 1a:159
  3. Merot et al. "Two types of K+ channels in the apical membrane of rabbit proximal tubule in primary culture." Biochim. Biophys. Acta (1989). 978:134
  4. Robertson et al. "Potassium channel modulators: Scientific applications and therapeutic promises." J. Med. Chem. (1990). 33(6):1529