konotoksiner

Konotoksiner (conotoxins) are a family of small, cysteine-rich peptide toxins produced by venomous marine cone snails (genus Conus). They are delivered by a specialized radular tooth into prey or potential threats. Cone snails possess a complex venom containing hundreds to thousands of distinct conotoxins, allowing rapid and highly selective disruption of neural signaling in prey.

Most konotoksiner peptides are 12-40 amino acids long and stabilized by multiple disulfide bonds. They are grouped into gene families and cysteine frameworks that correlate with their pharmacological targets. Notable toxin classes include alpha-conotoxins, which block nicotinic acetylcholine receptors; omega-conotoxins, which inhibit voltage-gated calcium channels; and other families such as mu-, delta-, kappa-, and others, which affect sodium or potassium channels and related receptors.

Mechanism and effects: Conotoxins act by selective blockade or modulation of neuronal ion channels and receptors, producing effects ranging from paralysis to analgesia. Their potency can be extremely high, with venom cocktails tailored to specific prey.

Medical research and applications: Conotoxins are valuable pharmacological tools and drug leads. The synthetic or recombinant omega-conotoxin MVIIA (ziconotide) is approved for the treatment of severe chronic pain via intrathecal administration. Other conotoxins are under development for analgesia, anesthesia, and neurological disorders, though delivery and safety remain challenges.

Ecology and evolution: Cone snails use venom both for prey capture and defense, and venom composition differs between species and even within populations. The rapid evolution of conotoxin genes contributes to a vast chemical diversity.