Effect of inserting charged peptide at NH₂-terminal on N-type inactivation of Kv1.4 channel

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• 作者：Zhuo Fan^a ; Zhenggang Zhang^a ; Mingyu Fu^a ; Zhi Qi^b ; ^{qizhi@xmu.edu.cn} ; Zhongju Xiao^a ; ^{xiaozj@fimmu.com}
• 关键词：Kv1.4 channel ; N-type inactivation ; &ldquo ; ball and chain&rdquo ; model ; Electrostatic interaction ; Voltage-gated ion channel ; Hydrophobic interaction
• 刊名：Biochimica et Biophysica Acta (BBA)/Biomembranes
• 出版年：2013
• 出版时间：March, 2013
• 年：2013
• 卷：1828
• 期：3
• 页码：990-996
• 全文大小：1165 K

文摘

Rapid inactivation of voltage-gated potassium channel plays an important role in shaping the electrical signaling in neurons and other excitable cells. N-type (¡°ball and chain¡±) inactivation, as the most extensively studied inactivation model, is assumed to be the inactivation mechanism of Kv1.4 channel. The inactivation ball inactivates the channel by interacting with the hydrophobic wall of inner pore and occluding it. Recently, we have proved that the electrostatic interaction between two charged segments in the NH₂-termainal plays an important role through promoting the inactivation process of the Kv1.4 channel. This study investigates the effect of inserting negatively or positively charged short peptides at NH₂-terminal on the inactivation of Kv1.4 channel. The results that inserting negatively-charged peptide (either myc or D-peptide) at different sites of NH₂-terminal, deceleraes inactivation process of Kv1.4 channel to a different extent with inserting site changing and that the mutant Kv1.4-D50 exhibits a more slower inactivation rate than Kv1.4-K50 further identified the role of electrostatic interactions in the ¡°ball and chain¡± inactivation mechanism.