Isolation and structural identification of a potassium ion channel Kv4.1 inhibitor SsTx-P2 from centipede venom

• Published in: Zhejiang da xue xue bao. Journal of Zhejiang University. Medical sciences. Yi xue ban Vol. 53; no. 2; pp. 194 - 200
• Main Authors: DU, Canwei, YUAN, Fuchu, DUAN, Xinyi, RONG, Mingqiang, MENG, Er, LIU, Changjun
• Format: Journal Article
• Language: Chinese; English
• Published: 25-04-2024
• ISSN: 1008-9292
• DOI: 10.3724/zdxbyxb-2023-0430

OBJECTIVESTo isolate a potassium ion channel Kv4.1 inhibitor from centipede venom, and to determine its sequence and structure.METHODSIon-exchange chromatography and reversed-phase high-performance liquid chromatography were performed to separate and purify peptide components of centipede venom, and their inhibiting effect on Kv4.1 channel was determined by whole-cell patch clamp recording. The molecular weight of isolated peptide Kv4.1 channel inhibitor was identified with matrix assisted laser desorption ionization-time-of-flight mass spectrometry; its primary sequence was determined by Edman degradation sequencing and two-dimensional mass spectrometry; its structure was established based on iterative thread assembly refinement online analysis.RESULTSA peptide SsTx-P2 was separated from centipede venom with the molecular weight of 6122.8, and its primary sequence consists of 53 amino acid residues NH2-ELTWDFVRTCCKLFPDKSECTKACATEFTGGDESRLKDVWPRKLRSGDSRLKD-OH. Peptide SsTx-P2 potently inhibited the current of Kv4.1 channel transiently transfected in HEK293 cell, with 1.0 μmol/L SsTx-P2 suppressing 95% current of Kv4.1 channel. Its structure showed that SsTx-P2 shared a conserved helical structure.CONCLUSIONSThe study has isolated a novel peptide SsTx-P2 from centipede venom, which can potently inhibit the potassium ion channel Kv4.1 and displays structural conservation.