About this Biochemistry, Genetics and Molecular Biology article

Synthesis and characterization of Pi4, a scorpion toxin from Pandinus imperator that acts on K+ channels by Sarrah M'Barek; Amor Mosbah; Guillaume Sandoz; Ziad Fajloun; Timoteo Olamendi‐Portugal; Hervé Rochat; François Sampieri; J. Iñaki Guijarro; Pascal Mansuelle; Muriel Delepierre; Michel De Waard; Jean‐Marc Sabatier is a Biochemistry, Genetics and Molecular Biology article available to read on EtoBox.

Pi4 is a 38‐residue toxin cross‐linked by four disulfide bridges that has been isolated from the venom of the __Chactidae__ scorpion __Pandinus imperator__. Together with maurotoxin, Pi1, Pi7 and HsTx1, Pi4 belongs to the α KTX6 subfamily of short four‐disulfide‐bridged scorpion toxins acting on K^+^ channels. Due to its very low abundance in venom, Pi4 was chemically synthesized in order to better characterize its pharmacology and structural properties. An enzyme‐based cleavage of synthetic Pi4 (sPi4) indicated half‐cystine pairings between Cys6–Cys27, Cys12–32, Cys16–34 and Cys22–37, which denotes a conventional pattern of scorpion toxin reticulation (Pi1/HsTx1 type). __In vivo__, sPi4 was lethal after intracerebroventricular injection to mice (LD~50~ of 0.2 μg per mouse). __In vitro__, addition of sPi4 onto __Xenopus laevis__ oocytes heterologously expressing various voltage‐gated K^+^ channel subtypes showed potent inhibition of currents from rat Kv1.2 (IC~50~ of 8 pm) and __Shaker__ B (IC~50~ of 3 nm) channels, whereas no effect was observed on rat Kv1.1 and Kv1.3 channels. The sPi4 was also found to compete with ^125^I‐labeled apamin for binding to small‐conductance Ca^2+^‐ac

Author

Sarrah M'Barek; Amor Mosbah; Guillaume Sandoz; Ziad Fajloun; Timoteo Olamendi‐Portugal; Hervé Rochat; François Sampieri; J. Iñaki Guijarro; Pascal Mansuelle; Muriel Delepierre; Michel De Waard; Jean‐Marc Sabatier

Publisher

John Wiley and Sons; Springer; Wiley (Blackwell Publishing); Springer-Verlag; Blackwell Publishing Inc.; Springer Verlag; Wiley; Springer Science and Business Media LLC (ISSN 1432-1327)

Published

2003

Language

EN

Field

Biochemistry, Genetics and Molecular Biology (Physical Sciences)