Kbot55, purified from Buthus occitanus tunetanus venom, represents the first member of a novel alpha-KTx subfamily

Rym Elfessi-Magouri (1) , Steve Peigneur (2) , Oussema Khamessi (1) , Najet Srairi-Abid (1) , Mohamed Elayeb (1) , Eva Cuypers (2) , Bea Garcia Mille (2) , Jan Tytgat (2) , Riadh Kharrat (1)

1 LR11IPT08 - Laboratoire des Venins et Biomolécules Thérapeutiques - Laboratory of Venoms and Therapeutic Biomolecules
2 Laboratory of Toxicology

Kbot55 is a 39 amino acid peptide isolated from the venom of the Tunisian scorpion Buthus occitanus tunetanus. This peptide is cross-linked by 3 disulfide bridges and has a molecular mass of 4128.65 Da. Kbot55 is very low represented in the venom and thus represents a challenge for biochemical characterization. In this study, Kbot55 has been subjected to a screening on ion channels expressed in Xenopus laevis oocytes. It was found that Kbot55 targets voltage-gated potassium channels with high affinity. Kbot55 shows very low amino acid identity with other scorpion potassium toxins and therefore was considered a bona fide novel type of scorpion toxin. Sequence alignment analysis indicated that Kbot55 is the first representative of the new alpha-Ktx31 subfamily and therefore was classified as alpha-Ktx31.1. (C) 2015 Elsevier Inc. All rights reserved.

Mots clés: Scorpion potassium toxins; alpha-KTx31 subfamily; Peptide; Scorpion envenomation; Disulfide bridges

Domaines: Sciences du Vivant [q-bio]

Rym Elfessi-Magouri, Steve Peigneur, Oussema Khamessi, Najet Srairi-Abid, Mohamed Elayeb, et al.. Kbot55, purified from Buthus occitanus tunetanus venom, represents the first member of a novel alpha-KTx subfamily. Peptides, 2016, 80, pp.4-8. ⟨10.1016/j.peptides.2015.05.015⟩. ⟨pasteur-01375001⟩