Slotoxin, αKTx1.11, a new scorpion peptide blocker of MaxiK channels that differentiates between α and α+β (β1 or β4) complexes

FEBS Letters

Possan, Lourival D¹  Garcia-Valdes, Jesus¹  Toro, Ligia²  Zamudio, Fernando Z¹ 

[1] Department of Molecular Recognition and Structural Biology, Institute of Biotechnology, National Autonomous University of Mexico, Avenida Universidad 2001, P.O. Box 510-3, Cuernavaca 62210, Mexico;Departments of Anesthesiology and Molecular and Medical Pharmacology, Brain Research Institute, University of California, Los Angeles, CA 90095-7115, USA

关键词: BK channel;    Scorpion toxin;    Pharmacology;    Potassium channel;    Centruroides noxius;   

DOI  :  10.1016/S0014-5793(01)02791-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A novel peptide from Centruroides noxius Hoffmann scorpion venom was isolated and sequenced. The 37 amino acid peptide belongs to the charybdotoxin sub-family (αKTx1) and was numbered member 11. αKTx1.11 has 75% sequence identity with iberiotoxin and 54% with charybdotoxin. αKTx1.11 revealed specificity for mammalian MaxiK channels (hSlo), thus, was named slotoxin. Slotoxin blocks the MaxiK pore-forming α subunit reversibly (K _d=1.5 nM). Slotoxin association with α+β (β1 or β4) channels was ∼10 times slower than iberiotoxin and charybdotoxin, leading to a lack of effect on α+β4 when tested at 100 nM for 5 min. Thus, slotoxin is a better tool to distinguish MaxiK α+β complexes.

【 授权许可】

Unknown