Synthesis of a photoaffinity labeling analogue of the inactivating peptide of the Shaker B potassium channel

FEBS Letters

López-Barneo, José³  Gavilanes, Francisco¹  Molina, Antonio³  Fernandez, Asia M.²  Encinar, Jose A.²  Gonzalez-Ros, Jose M.² 

[1] Department of Biochemistry, Faculty of Chemical Sciences, Complutensis University, 28040 Madrid, Spain;Department of Neurochemistry and Institute of Neurosciences, University of Alicante, 03080 Alicante, Spain;Department of Physiology and Biophysics, School of Medicine, Avda. Sánchez Pizjuán 4, E-41009 Sevilla, Spain

关键词: Ion channel inactivation;    Inactivating peptide;    conformation;    Photoactivatable peptide analog;    Photoaffinity labeling;   

DOI  :  10.1016/S0014-5793(96)01186-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A photoactivatable derivative of the inactivating peptide of the Shaker B potassium channel (ShB peptide) has been synthesized from ShB peptide containing an added cysteine residue at the peptide carboxy-terminus and 1-(p-azidosalicylamido)-4-(iodoacetamido)butane. The peptide derivative restores rapid inactivation in the deletion mutant Shaker BΔ6–46 potassium channel in a manner indistinguishable from that of the wild-type ShB peptide. Also, both peptides display similar conformational behavior when challenged in vitro by an artificial model target that partly imitates the properties of the putative receptor site for the inactivating peptide in the Shaker B potassium channel. Therefore, we conclude that both functionally and conformationally the photoreactive peptide derivative is an adequate analogue of the wild-type ShB peptide, suitable for photoaffinity labeling of its binding site in the Shaker B potassium channel. Moreover, because the ShB peptide also serves as an efficient inactivating peptide for a large variety of other potassium channels, it appears that the photoreactive analogue may be useful to explore homologous sites in many different channel proteins.

【 授权许可】

Unknown