Κ-Bungarotoxin

1KBA dimer

Κ-Bungarotoxin (κ-Bgt) is a neurotoxin derived from the venom of the Bungarus multicinctus, commonly known as the many-banded krait. This toxin is a member of the bungarotoxin family, which includes several other neurotoxins such as α-Bungarotoxin and β-Bungarotoxin. κ-Bungarotoxin specifically targets the nicotinic acetylcholine receptors (nAChRs) in the nervous system, leading to paralysis and potentially fatal respiratory failure.

Structure and Function

κ-Bungarotoxin is a protein composed of multiple subunits that form a complex structure. It binds to the nicotinic acetylcholine receptors at the neuromuscular junction, inhibiting the action of acetylcholine, a neurotransmitter essential for muscle contraction. By blocking these receptors, κ-Bungarotoxin prevents the transmission of nerve impulses to muscles, resulting in paralysis.

Mechanism of Action

The primary mechanism of action of κ-Bungarotoxin involves its high affinity binding to the nicotinic acetylcholine receptors. This binding is irreversible, leading to a prolonged blockade of the receptor sites. The inhibition of acetylcholine binding prevents the depolarization of the muscle membrane, which is necessary for muscle contraction. This blockade can cause severe muscle weakness and respiratory failure if not treated promptly.

Medical and Research Applications

κ-Bungarotoxin has been extensively used in neuroscience research to study the function and structure of nicotinic acetylcholine receptors. Its ability to selectively bind to these receptors makes it a valuable tool for mapping receptor locations and understanding their role in various physiological processes. Additionally, κ-Bungarotoxin has potential therapeutic applications in the treatment of conditions involving dysfunctional nicotinic acetylcholine receptors.

Safety and Handling

Due to its potent neurotoxic effects, κ-Bungarotoxin must be handled with extreme caution in laboratory settings. Proper safety protocols, including the use of personal protective equipment and secure storage, are essential to prevent accidental exposure.

Related Toxins

• α-Bungarotoxin
• β-Bungarotoxin
• δ-Bungarotoxin

See Also

• Bungarus multicinctus
• Neurotoxin
• Nicotinic acetylcholine receptor
• Acetylcholine