Calciseptine

3D model of calciseptine structure

Calciseptine is a polypeptide toxin derived from the venom of the black mamba (Dendroaspis polylepis), a highly venomous snake found in parts of sub-Saharan Africa. This toxin is known for its ability to block L-type calcium channels, which are essential for various physiological processes, including muscle contraction and neurotransmitter release.

Structure and Function

Calciseptine is composed of 60 amino acids and contains four disulfide bonds, which contribute to its stability and function. The primary action of calciseptine is the inhibition of L-type calcium channels, which are a type of voltage-gated calcium channel found in the heart, skeletal muscle, and neurons. By blocking these channels, calciseptine can interfere with the normal influx of calcium ions into cells, leading to various physiological effects.

Mechanism of Action

Calciseptine binds to the L-type calcium channels with high affinity, preventing the influx of calcium ions into the cell. This inhibition can lead to a decrease in muscle contraction, reduced neurotransmitter release, and altered cardiac function. The specific binding site of calciseptine on the L-type calcium channel is thought to be within the pore-forming subunit of the channel, which is critical for its function.

Applications in Research

Due to its specific action on L-type calcium channels, calciseptine is used as a tool in pharmacological and physiological research. It helps scientists understand the role of these channels in various tissues and can be used to study diseases related to calcium channel dysfunction, such as cardiac arrhythmias, hypertension, and certain neurological disorders.

Potential Therapeutic Uses

While calciseptine itself is not used as a therapeutic agent, its mechanism of action has inspired the development of calcium channel blockers, a class of drugs used to treat conditions like hypertension, angina, and certain types of arrhythmias. These drugs mimic the inhibitory effects of calciseptine on L-type calcium channels, providing therapeutic benefits in managing these conditions.

Safety and Toxicity

As a component of black mamba venom, calciseptine is highly toxic and can cause severe physiological effects if introduced into the body. However, in controlled research settings, it is used in small, precise quantities to study its effects without causing harm.

Related Pages

• Black mamba
• L-type calcium channel
• Voltage-gated calcium channel
• Calcium channel blocker
• Cardiac arrhythmia
• Hypertension
• Neurotransmitter