Analysis of the water-ion coupling ratio during ion-selective permeation through ion channels

• Project/Area Number: 21790198
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Single-year Grants
• Research Field: General physiology
• Research Institution: University of Fukui
• Principal Investigator: IWAMOTO Masayuki University of Fukui, 医学部, 助教 (40452122)
• Project Period (FY): 2009 – 2010
• Project Status: Completed (Fiscal Year 2010)
• Budget Amount: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2010: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2009: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000)
• Keywords: 生体膜 / チャネル / 透過

Research Abstract

In this study we succeeded in developing the improved method to measure the streaming potential that generates upon ion-selective permeation through ion channels. Extensive analysis of the streaming potential using KcsA potassium channel revealed that the number of water molecules accompanying with a permeating ion is modulated by ion species and its concentration. Based on the experimentally obtained water-ion coupling ratios, we presented here more dynamic and intuitive permeation model for the potassium channels than the conventional model.

Research Products

• [Journal Article] Cycle flux algebra for ion and water flux through the KcsA channel single-file pore links microscopic trajectories and macroscopic observables (2011)
  • Author(s): Oiki S., Iwamoto M., Sumikama T.
  • Journal Title: PLoS ONE 6
  • NAID: 120003072326
  • Peer Reviewed
• [Journal Article] Cycle flux algebra for ion and water flux through the KcsA channel single-filepore links microscopic trajectories and macroscopic observables (2011)
  • Author(s): S.Oiki, et al.
  • Journal Title: PLoS ONE Volume: 6
  • Peer Reviewed
• [Journal Article] A cytotoxic peptide from a marine sponge exhibits ion channel activity through vectorial-insertion into the membrane (2010)
  • Author(s): Iwamoto M., Shimizu H., Muramatsu I., Oiki S.
  • Journal Title: FEBS Lett. 584 Pages: 3995-3999
  • Peer Reviewed
• [Journal Article] A mesoscopic approach to understanding the mechanisms underlying the ion permeation on the discrete-state diagram (2010)
  • Author(s): Oiki S., Iwamoto M., Sumikama T.
  • Journal Title: J.Gen.Physiol. 136 Pages: 363-365
  • Peer Reviewed
• [Journal Article] A cytotoxic peptide from a marine sponge, polytheonamide B: I.Channel activity and vectorial-insertion into the membrane (2010)
  • Author(s): Iwamoto M., Shimizu H., Muramatsu I., Matsunaga S., Oiki S.
  • Journal Title: Biophys.J. 98
• [Journal Article] A cytotoxic peptide from a marine sponge, polytheonamide B; II.Properties for ion conduction and voltage dependent gating (2010)
  • Author(s): Iwamoto M., Shimizu H., Muramatsu I., Matsunaga S., Oiki S.
  • Journal Title: Biophys.J. 98
• [Journal Article] A cytotoxic peptide from a marine sponge exhibits ion channel activity through vectorial-insertion into the membrane (2010)
  • Author(s): M.Iwamoto, et al.
  • Journal Title: FEBS Lett. Volume: 584 Pages: 3995-3999
  • Peer Reviewed
• [Journal Article] A mesoscopic approach to understanding the mechanisms underlying the ion permeation on the discrete-state diagram (2010)
  • Author(s): S.Oiki, et al.
  • Journal Title: J.Gen.Physiol. Volume: 136 Pages: 363-365
  • Peer Reviewed
• [Journal Article] The water-ion coupling ratio for ion permeation through the KcsA potassium channel: Dependencies on concentration and species of permeating ions (2009)
  • Author(s): Iwamoto M., Shimizu H., Oiki S.
  • Journal Title: Biophys.J. 96suppl.
• [Journal Article] Ion distribution in the open KcsA channel evaluated by the streaming potential (2009)
  • Author(s): Iwamoto M., Shimizu H., Oiki S.
  • Journal Title: J.Physiol.Sci. 59suppl. Pages: 256-256
• [Journal Article] The water-ion coupling ratio for ion permeation through the KcsA potassiumchannel : Dependencies on concentration and species of permeatingions (2009)
  • Author(s): M.Iwamoto, et al.
  • Journal Title: Biophys. J. 96 suppl.
• [Journal Article] Ion distribution in the open KcsA channel evaluated by the streaming potential (2009)
  • Author(s): M.Iwamoto, et al.
  • Journal Title: J.Physiol. Sci. 59 suppl. Pages: 256-256
• [Presentation] 新奇βヘリックス型ペプチド・ポリセオナミドBのイオンチャネル活性 (2010)
  • Author(s): 岩本真幸
  • Organizer: 次世代スーパーコンピュータプロジェクト ナノ分野グランドチャレンジ研究開発ナノ統合拠点第20回連続研究会 イオンチャネルNo.2
  • Place of Presentation: 福井
  • Year and Date: 2010-12-02
• [Presentation] 新奇異常ペプチドの一方向膜挿入による一価陽イオン選択性ポアの形成 (2010)
  • Author(s): 岩本真幸, 清水啓史, 村松郁延, 松永茂樹, 老木成稔
  • Organizer: 日本生物物理学会第48回年会
  • Place of Presentation: 仙台
  • Year and Date: 2010-09-22
• [Presentation] 海綿由来細胞毒性ペプチドポリセオナミドBのイオンチャネル活性および細胞膜挿入機構 (2010)
  • Author(s): 岩本真幸, 清水啓史, 村松郁延, 松永茂樹, 老木成稔
  • Organizer: 第87回日本生理学会大会
  • Place of Presentation: 盛岡
  • Year and Date: 2010-05-20
• [Presentation] A cytotoxic peptide from a marine sponge, polytheonamide B: I.Channel activity and vectorial-insertion into the membrane (2010)
  • Author(s): Iwamoto M., Shimizu H., Muramatsu I., Matsunaga S., Oiki S.
  • Organizer: Biophysical Society 54th Annual Meeting
  • Place of Presentation: San Francisco, USA
  • Year and Date: 2010-02-21
• [Presentation] A cytotoxic peptide from a marine sponge, polytheonamide B; II.Properties for ion conduction and voltage dependent gating (2010)
  • Author(s): Iwamoto M., Shimizu H., Muramatsu I., Matsunaga S., Oiki S.
  • Organizer: Biophysical Society 54th Annual Meeting
  • Place of Presentation: San Francisco, USA
  • Year and Date: 2010-02-21
• [Presentation] A cytotoxic peptide from a marine sponge, polytheonamide B : II. Properties for ion conduction and voltage dependent gating (2010)
  • Author(s): M.Iwamoto
  • Organizer: 米国生物物理学会第54回年会
  • Place of Presentation: Moscone Convention Center(サンフランシスコ)
  • Year and Date: 2010-02-21
• [Presentation] 流動電位から解析した開状態KcsAカリウムチャネル内のイオンと水の分布 (2009)
  • Author(s): 岩本真幸, 清水啓史, 老木成稔
  • Organizer: 日本生物物理学会第47回年会
  • Place of Presentation: 徳島
  • Year and Date: 2009-11-01
• [Presentation] 流動電位から解析した開状態KcsAカリウムチャネル内のイオンと水の分布 (2009)
  • Author(s): 岩本真幸
  • Organizer: 日本生物物理学会第47回年会
  • Place of Presentation: アスティとくしま(徳島)
  • Year and Date: 2009-11-01
• [Presentation] Ion distribution in the open KcsA channel evaluated by the streaming potential (2009)
  • Author(s): Iwamoto M, Shimizu H, Oiki S.
  • Organizer: 第36回国際生理学会世界大会
  • Place of Presentation: 京都
  • Year and Date: 2009-07-29
• [Presentation] Ion distribution in the open KcsA channel evaluated by the streaming potential (2009)
  • Author(s): M.Iwamoto
  • Organizer: 第36回国際生理学会世界大会
  • Place of Presentation: 京都国際会議場(京都)
  • Year and Date: 2009-07-29