Conotoxin I2-superfamily (IPR020242)

Short name: Conotoxin_I2-superfamily

Overlapping homologous superfamilies


Family relationships



Members of this family display a XI cysteine pattern (C-C-CC-CC-C-C) and belong to the I2- superfamily conotoxins. Family members such as Kappa-conotoxin ViTx (Q7YZS9) and Kappa-conotoxin SrXIA (P0C615) inhibit voltage gated potassium channels (Kv) [PMID: 25522317].

Cone snail toxins, conotoxins, are small peptides with disulphide connectivity, that target ion-channels or G-protein coupled receptors. Based on the number and pattern of disulphide bonds and biological activities, conotoxins can be classified into several families [PMID: 11478951]. Omega, delta and kappa families of conotoxins have a knottin or inhibitor cystine knot scaffold. The knottin scaffold is a very special disulphide through disulphide knot, in which the III-VI disulphide bond crosses the macrocycle formed by two other disulphide bonds (I-IV and II-V) and the interconnecting backbone segments, where I-VI indicates the six cysteine residues starting from the N terminus; for further information see the KNOTTIN database (

Conotoxins represent a unique arsenal of neuropharmacologically active peptides that have been evolutionarily tailored to afford unprecedented and exquisite selectivity for a wide variety of ion-channel subtypes. The toxins derived from cone snails are currently being investigated for the treatment of chronic pain, epilepsy, cardiovascular diseases, psychiatric and movement disorders, spasticity, cancer, stroke as well as an anesthetic agent. Several potential analgesic and anti-inflammatory peptides from conotoxin families have been identified and patented [PMID: 10903392, PMID: 15225557], e.g. Conus magus (Magus cone) (Magician's cone snail) omega-conotoxin MVIIa (Ziconotide), which is used for the treatment of chronic pain, Conus catus (Cat cone) omega-conotoxin CVID, which is tested for treating severe morphine-resistant pain stress, and Conus geographus (Geography cone) (Nubecula geographus) omega-conotoxin GVIA, which may exert antagonistic effects against beta-endorphin induced anti-nociception.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.