New ShK-Like Peptide from the Jellyfish <em>Nemopilema nomurai</em> Has Human Potassium Voltage-Gated Channel-Blocking Activity

• DOI: 10.20944/preprints202309.1253.v1
• Publication Date: 2023-09-20T06:02:03Z
• Authors: Ye-Ji Kim; Yejin Jo; Seung Eun Lee; Jungeun Kim; Jae-Pil Choi; Nayoung Lee; Hyokyoung Won; Dong Ho Woo; Seungshic Yum
• Keywords: Voltage-gated potassium channel; Potassium channel blocker; Coding region

We have identified a new human voltage-gated potassium channel (hKv1.3) blocker, NnK-1, in the jellyfish Nemopilema nomurai, based on its genomic information. The gene sequence encoding NnK-1 contains 5,408 base pairs, with five introns and six exons. coding of precursor is 894 nucleotides long encodes 297 amino acids, containing presumptive ShK-like peptides. An electrophysiological assay demonstrated that chemically synthesized fifth peptide, an effective hKv1.3 blocker. A multiple alignment cnidarian Shk-like peptides, which Kv1.3-blocking activity, revealed four residues (3Asp, 25Lys, 33Lys, 34Thr) together cysteine residues, are conserved. Therefore, we hypothesize these crucial for binding toxins to channels.