Effect of inserting charged peptide at NH(2)-terminal on N-type inactivation of Kv1.4 channel

• Published in: Biochimica et biophysica acta Vol. 1828; no. 3; pp. 990 - 996
• Main Authors: Fan, Zhuo, Zhang, Zhenggang, Fu, Mingyu, Qi, Zhi, Xiao, Zhongju
• Format: Journal Article
• Language: English
• Published: Netherlands 01.03.2013
• Subjects: Amino Acid Sequence; Animals; Biophysics - methods; CHO Cells; Cricetinae; Electrophysiology - methods; Green Fluorescent Proteins - metabolism; Ions; Kv1.4 Potassium Channel - chemistry; Kv1.4 Potassium Channel - metabolism; Membrane Potentials; Molecular Sequence Data; Mutation; Peptides - chemistry; Protein Structure, Tertiary; Proto-Oncogene Proteins c-myc - chemistry; Sequence Homology, Amino Acid; Static Electricity
• ISSN: 0006-3002
• DOI: 10.1016/j.bbamem.2012.11.016

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 NH(2)-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 NH(2)-terminal on the inactivation of Kv1.4 channel. The results that inserting negatively-charged peptide (either myc or D-peptide) at different sites of NH(2)-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.