Delta atracotoxin

Delta atracotoxin is a potent neurotoxic peptide found in the venom of the Australian funnel-web spider, particularly the Sydney funnel-web spider (Atrax robustus). This toxin is known for its ability to affect the nervous system by modifying the activity of ion channels, leading to severe physiological effects in envenomated organisms.

Structure

Delta atracotoxin is a small peptide consisting of 42 amino acids. The structure of this toxin is stabilized by three disulfide bridges, which contribute to its high stability and resistance to degradation. The molecular structure, as depicted in the image, shows a compact, globular form typical of many peptide toxins.

Mechanism of Action

Delta atracotoxin primarily targets voltage-gated sodium channels in the nervous system. By binding to these channels, the toxin prevents their inactivation, leading to prolonged depolarization of the nerve cell membrane. This results in uncontrolled firing of action potentials, causing symptoms such as muscle spasms, pain, and potentially life-threatening conditions like respiratory failure.

Clinical Significance

Envenomation by the Sydney funnel-web spider can lead to severe symptoms in humans, including autonomic and neuromuscular effects. The development of an effective antivenom has significantly reduced the mortality rate associated with bites from these spiders. The antivenom works by neutralizing the effects of the toxin, allowing for recovery of normal nerve function.

Research and Applications

Delta atracotoxin has been the subject of extensive research due to its unique properties and potential applications. Studies have explored its use as a tool for understanding ion channel function and as a lead compound for developing new pharmacological agents. The specificity of the toxin for certain sodium channel subtypes makes it a valuable model for drug development targeting neurological disorders.

Related Pages

• Spider venom
• Neurotoxin
• Ion channel
• Antivenom