a blocker of voltage-sensitive K⁺ channels with potent convulsant activity.

22-amino acid peptide with a strongly basic character and 2 disulfide bridges, from Apis mellifera bee venom.

• Molecular Weight : 2,593 Da.
  
  
• Solubility in : well in water and saline.
  
  
• Purity min. : (percent by weight)
  MCD Peptide: 65 Peptidic contaminants: 2
  Acetate: 18 H₂O: 15
  
  
• Biological Activity : Mast cell degranulating activity: causes histamine release with half-maximal effects in rat peritoneal mast cell preparations at concentrations of 2 X 10^-8 M.
  MCD Peptide binds with high affinity (K_d = 150 pM) to rat synaptic membranes. This binding induces the inhibition of a voltage sensitive K⁺ current and produces hippocampal responses (long term potentiation, Theta rhythm and epileptiform seizures).
  
  
• Toxicity (LD₅₀) : mice (intracerebroventricularly): 1.5 ng/g.
  rats (intracerebroventricularly): 6.8 ng/g.
  
  
• Storage recommendations : 125 µl of distilled water added to a 50 µg vial gives a 100 µM MCD Peptide solution. Store preferably at -20°C. The solution can be freezed and thawed.
  
  
• CAS Reg. No. : 32908-73-9
  
  
• Bibliography :
  
  1. Taylor et al., J. Biol. Chem. (1984). 259:13957-13967
  2. Bidard et al. Brain Res. (1987). 418:235-244
  3. Cherubini et al., Nature (1987) 328:70-73