The new strategy of screening venom peptides aiming at ion channel

The ion channel is an important drug target of pain, autoimmune diseases, tumor and other diseases. The toxin polypeptide of animals is formed in the evolution of hundreds of millions of years, and it is rich in active ion channels. There is an urgent need to find a way to quickly discover toxin peptides aiming at ion channels.

Professor Richard Lerner from the Institute of Immunochemistry of the Shanghai University of Science and Technology (SIAIS) has innovatively proposed an autocrine-based screening method to screen high-throughput peptides for ion channels. The researchers first constructed a set of signaling systems based on autoadhesive detection of ion channels binding to the toxin polypeptide and using recombinant mouse proteins. In this system, the toxin polypeptide can be anchored to the cell membrane by the platelet-derived growth factor receptor transmembrane domain PDGFR-TM and is fused to the TEV protease at the intracellular end of the transmembrane domain. The ion channels are linked to the artificial transcription factor GAL4-VP16 by the TEV protease substrate sequence. TEV protease cleaves its substrate to release GAL4-VP16 and activates the expression of fluorescent protein reporter gene when it binds to the toxin polypeptide. Fluorescent protein-expressing cells can be sorted by flow cytometry.

Using this method, the researchers screened a library of 589 virulent polypeptides for ion channel Kv1.3. They found that 25 of the 27 enriched toxin polypeptides that were the most enriched in the screening were known as Kv1.3 blocker, and their experiments confirmed that the Clltx1 polypeptide from scorpion venom was a novel and highly effective Kv1.3 antagonist. The system further reconstructed the ShK protein from the sea anemone toxin and constructed nearly one million ShK analogues with long-acting properties for screening. The screened ShK analogues showed high Kv1.3 antagonistic potency and no off-target effects on a series of ion channel molecules which are highly similar to Kv1.3. Flarebio offers superior recombinant proteins such as recombinant App at good prices.