Functional equilibrium of the KcsA structure revealed by NMR

Shunsuke Imai, Masanori Osawa, Kenichiro Mita, Shou Toyonaga, Asako Machiyama, Takumi Ueda, Koh Takeuchi, Shigetoshi Oiki, Ichio Shimada

研究成果: Article査読

42 被引用数 (Scopus)

抄録

KcsA is a tetramericK+ channel that is activated by acidic pH. Under open conditions of the helix bundle crossing, the selectivity filter undergoes an equilibrium between permeable and impermeable conformations. Here we report that the population of the permeable conformation (pperm) positively correlates with the tetrameric stability and that the population in reconstituted high density lipoprotein, where KcsA is surrounded by the lipid bilayer, is lower than that in detergent micelles, indicating that dynamic properties of KcsA are different in these two media. Perturbation of the membrane environment by the addition of 1-3% 2,2,2-trifluoroethanol increases pperm and the open probability, revealed by NMR and single-channel recording analyses. These results demonstrate that KcsA inactivation is determined not only by the protein itself but also by the surrounding membrane environments.

本文言語English
ページ(範囲)39634-39641
ページ数8
ジャーナルJournal of Biological Chemistry
287
47
DOI
出版ステータスPublished - 2012 11 16
外部発表はい

ASJC Scopus subject areas

  • 生化学
  • 分子生物学
  • 細胞生物学

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