Ω-Agatoxin IVA

Ω-Agatoxin IVA is a peptide toxin derived from the venom of the funnel-web spider Agelenopsis aperta. This toxin is a potent and selective blocker of certain voltage-gated calcium channels, specifically the P/Q-type calcium channels, which are critical for neurotransmitter release in the central nervous system.

Structure and Function

Ω-Agatoxin IVA is a member of the agatoxin family of toxins, which are known for their ability to modulate ion channels. The structure of Ω-Agatoxin IVA consists of a complex arrangement of amino acids that form a stable three-dimensional conformation, allowing it to interact specifically with its target channels.

The primary function of Ω-Agatoxin IVA is to inhibit the P/Q-type calcium channels. These channels are predominantly found in the presynaptic terminals of neurons and are essential for the release of neurotransmitters. By blocking these channels, Ω-Agatoxin IVA effectively reduces synaptic transmission, which can be useful in studying the role of these channels in various physiological and pathological processes.

Mechanism of Action

Ω-Agatoxin IVA binds to the α1A subunit of the P/Q-type calcium channels, which are also known as Cav2.1 channels. This binding prevents the influx of calcium ions into the presynaptic terminal, thereby inhibiting the release of neurotransmitters such as glutamate and GABA. The blockade of these channels by Ω-Agatoxin IVA is highly specific and does not significantly affect other types of calcium channels, such as L-type or N-type channels.

Applications in Research

Due to its specificity, Ω-Agatoxin IVA is a valuable tool in neurophysiological research. It is used to:

• Study synaptic transmission: By selectively blocking P/Q-type calcium channels, researchers can investigate the role of these channels in neurotransmitter release and synaptic plasticity.
• Explore neurological disorders: Dysfunctions in P/Q-type calcium channels are implicated in various neurological disorders, including epilepsy and ataxia. Ω-Agatoxin IVA can be used to model these conditions in experimental settings.
• Develop therapeutic agents: Understanding how Ω-Agatoxin IVA interacts with calcium channels can aid in the design of new drugs targeting these channels for therapeutic purposes.

Safety and Handling

As a potent neurotoxin, Ω-Agatoxin IVA must be handled with care in a laboratory setting. Appropriate safety measures, including the use of personal protective equipment and proper disposal procedures, should be followed to prevent accidental exposure.

Also see

• Calcium channel blocker
• Neurotransmitter release
• Voltage-gated calcium channel
• Spider venom

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