Animal venoms are increasingly recognized as valuable molecular toolboxes for the discovery of novel compounds with therapeutic potential. Among the most promising therapeutic targets for venom-derived molecules are voltage-gated ion channels, which are involved in multiple physiological processes and implicated in various diseases. Here, we report the discovery of novel peptides from the venom of Physalia physalis, predicted to target vertebrate Kv channels.

A proteomic analysis of P. physalis tentacles led to the identification of 30 ShK-like peptides belonging to the ShK family, based on their conserved primary structure and cysteine-rich scaffold. Some of them showed potential as therapeutic leads due to their ability to selectively target specific Kv channel subtypes. Their 3D structures were predicted using the deep-learning-based tool AlphaFold and subjected to molecular docking against a panel of human potassium channels. Several candidates exhibited low binding energies and high predicted specificity for the Kv1.3 channel. A high-affinity peptide was produced in recombinant form and functionally validated through whole-cell patch-clamp electrophysiology, confirming its inhibitory activity against Kv1.3 at nanomolar concentrations. Additionally, a radioligand competition assay with α-dendrotoxin in human brain tissue revealed low competition for Kv1.1, Kv1.2, and Kv1.6, supporting the peptide’s selectivity.

These findings underscore the potential of P. physalis venom components as a source of new and selective ion channel modulators. Given the role of the Kv1.3 channel in a range of human diseases—including pain, autoimmune disorders, and neurological conditions—these molecules hold great promise for the development of new therapeutic drugs.