Agitoxin

A peptide toxin from scorpion venom

Agitoxin is a peptide toxin derived from the venom of the scorpion Leiurus quinquestriatus. It is known for its ability to block potassium channels, specifically the voltage-gated potassium channels in nerve cells. This property makes agitoxin a valuable tool in neuroscience research for studying the function of these channels.

Structure

Agitoxin is a small peptide consisting of 38 amino acid residues. The structure of agitoxin is stabilized by three disulfide bridges, which contribute to its high stability and specificity in binding to potassium channels. The three-dimensional structure of agitoxin has been determined using X-ray crystallography and NMR spectroscopy.

File:1agt.png

The crystal structure of Agitoxin.

Mechanism of Action

Agitoxin exerts its effects by binding to the outer vestibule of the potassium channel, thereby blocking the flow of potassium ions through the channel. This blockage prevents the normal repolarization of the neuronal membrane, which can affect action potentials and neurotransmission. The specificity of agitoxin for certain potassium channels makes it a useful tool for identifying and characterizing these channels in various tissues.

Applications in Research

Due to its specific action on potassium channels, agitoxin is used in research to study the physiological roles of these channels in different cell types. It is particularly useful in the study of neuronal excitability, cardiac electrophysiology, and muscle contraction. Researchers use agitoxin to investigate the effects of potassium channel dysfunction in various diseases, including epilepsy, arrhythmias, and muscle disorders.

Related pages

• Potassium channel
• Scorpion venom
• Neurotoxin
• Ion channel

Gallery

• Alignment of Agitoxin with other toxins.
  Alignment of Agitoxin with other toxins.

Agitoxin

• File:1agt.png
• File:Agitoxinalignment.png