Primary structure of a potassium channel toxin from the sea anemone Actinia equina

FEBS Letters

Minagawa, Sonomi¹  Ishida, Masami¹  Shiomi, Kazuo¹  Nagashima, Yuji¹ 

[1] Department of Food Science and Technology, Tokyo University of Fisheries, Konan-4, Minato-ku, Tokyo 108-8477, Japan

关键词: Amino acid sequence;    Potassium channel toxin;    Sea anemone;    Actinia equina;   

DOI  :  10.1016/S0014-5793(98)00403-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A potassium channel toxin (AeK) was isolated from the sea anemone Actinia equina by gel filtration on Sephadex G-50 and reverse-phase HPLC on TSKgel ODS-120T. AeK and α-dendrotoxin inhibited the binding of ¹²⁵I-α-dendrotoxin to rat synaptosomal membranes with IC₅₀ of 22 and 0.34 nM, respectively, indicating that AeK is about sixty-five times less toxic than α-dendrotoxin. The complete amino acid sequence of AeK was elucidated; it is composed of 36 amino acid residues including six half-Cys residues. The determined sequence showed that AeK is analogous to the three potassium channel toxins from sea anemones (BgK from Bunodosoma granulifera, ShK from Stichodactyla helianthus and AsKS from Anemonia sulcata), with an especially high sequence homology (86%) with AsKS.

【 授权许可】

Unknown