多価カチオンによって媒介される酸性蛋白質間引力の制御と動的秩序構造

• Project Area: Dynamical ordering of biomolecular systems for creation of integrated functions
• Project/Area Number: 26102533
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Science and Engineering
• Research Institution: Kyushu University
• Principal Investigator: 秋山 良 九州大学, 理学(系)研究科(研究院), 准教授 (60363347)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥5,720,000 (Direct Cost: ¥4,400,000、Indirect Cost: ¥1,320,000); Fiscal Year 2015: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000); Fiscal Year 2014: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
• Keywords: マクロアニオン間実効引力 / 多価カチオン / タンパク質間相互作用 / 相図 / 電解質溶液 / 積分方程式理論 / シミュレーション / 蛋白質間相互作用 / 国際情報交換

Outline of Annual Research Achievements

前年度までに積分方程式理論を用いて得られている実効相互作用を元に、第２ビリアル係数の計算、シミュレーションを行い、実験的に求められている同符号に帯電したタンパク質の凝集挙動の再現に成功した。これが最も重要な成果であったと思う。少々具体的に述べると、酸性タンパク質は負に帯電している球状タンパク質であるが、金属多価カチオンの添加により凝集する。この凝集挙動は金属多価カチオンがmMオーダーでこの起き、更に濃度が高くなると凝集が起きにくくなる。また、凝集が起きはじめる濃度は、タンパク質分子の濃度が高くなるに従って高くなる。我々は蛋白質（アクチン）を荷電剛体球としてモデル化して来たが、このレベルのモデルでもこの相図がかなり適切に計算される事が分かった。また、荷電剛体球の電荷を増減する事で、凝集の起きる濃度域がシフトする事が分かった。ADP結合型アクチンとATP結合型アクチンのフィラメントへの結合能に差があるが、今回考えている実効相互作用がその現象を制御しているという仮説をサポートする結果である。
この実効相互作用に基づいて、アクチン様タンパク質分子構造を仮定してトレッドミル運動の粗視化シミュレーションの計算まで行う予定であったがそれが完成しなかった事が未到達課題となった。これは今後も継続して挑戦したい。

Research Progress Status

27年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

27年度が最終年度であるため、記入しない。

Research Products

• [Journal Article] Effects of Solvation Structure on Diffusion of Large Particle in Binary Mixture Studied by Perturbation Theory (2014)
  • Author(s): Yuka Nakamura, Akira Yoshimori, and Ryo Akiyama
  • Journal Title: J. Mol. Liq. Volume: 200 Pages: 85-88
  • DOI: 10.1016/j.molliq.2014.06.021
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Attractive interaction between macroanions mediated by multivalent cations in biological fluids (2014)
  • Author(s): Shingo Fujihara, and Ryo Akiyama
  • Journal Title: J. Mol. Liq. Volume: 200 Pages: 89-94
  • DOI: 10.1016/j.molliq.2014.06.022
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Hidden peak of radial distribution function and effective attraction between like-charged proteins caused by translational motion of solvent molecules (2014)
  • Author(s): Ryo Akiyama, Takumi Yamashita, and Shingo Fujihara
  • Journal Title: J. Mol. Liq. Volume: 200 Pages: 72-76
  • DOI: 10.1016/j.molliq.2014.06.004
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Choice of the center of water molecules in calculations of partial molar volume of single ions immersed in water: A molecular simulation study (2014)
  • Author(s): Yuichi Kawabata, and Ryo Akiyama
  • Journal Title: J. Mol. Liq. Volume: 200 Pages: 67-71
  • DOI: 10.1016/j.molliq.2014.05.022
  • Peer Reviewed
• [Journal Article] Perturbation Theory of Large-Particle Diffusion in a Binary Solvent Mixture (2014)
  • Author(s): Yuka Nakamura, Akira Yoshimori, Ryo Akiyama
  • Journal Title: Journal of the Physical Society of Japan Volume: (印刷中) Issue: 6 Pages: 064601-064601
  • DOI: 10.7566/jpsj.83.064601
  • Peer Reviewed
• [Presentation] 同符号コロイド粒子間相互作用における同符号イオンの価数依存性 (2016)
  • Author(s): 山下拓海、秋山 良
  • Organizer: 日本物理学会 第71回年次大会
  • Place of Presentation: 仙台
  • Year and Date: 2016-03-19
• [Presentation] 電解質溶液中の同符号荷電コロイド粒子間実効引力と蛋白質溶液の相図 (2015)
  • Author(s): 秋山良
  • Organizer: 慶応義塾大学理工学部物理学科談話会
  • Place of Presentation: 横浜
  • Year and Date: 2015-11-24
  • Invited
• [Presentation] Effective attraction between negatively charged sites on proteins and ordering of proteins in an electrolyte solution (2015)
  • Author(s): Ryo Akiyama
  • Organizer: The 4th International Symposium “Dynamical Ordering of Biomolecular Systems for creation of integrated functions”(新学術領域研究『動的秩序と機能』第4回国際シンポジウム)
  • Place of Presentation: Fukuoka
  • Year and Date: 2015-11-22
  • Int'l Joint Research / Invited
• [Presentation] Aggregation of acidic proteins and effective attraction between like-charged particles (2015)
  • Author(s): Takuto Sawayama, Ryo Akiyama
  • Organizer: The 4th International Symposium “Dynamical Ordering of Biomolecular Systems for creation of integrated functions”(新学術領域研究『動的秩序と機能』第4回国際シンポジウム)
  • Place of Presentation: Fukuoka
  • Year and Date: 2015-11-22
  • Int'l Joint Research
• [Presentation] Effects of depletion interaction on the crystallization
 (2015)
  • Author(s): Ayumi Suematsu, Akira Yoshimori, Ryo Akiyama
  • Organizer: The 4th International Symposium “Dynamical Ordering of Biomolecular Systems for creation of integrated functions”(新学術領域研究『動的秩序と機能』第4回国際シンポジウム)
  • Place of Presentation: Fukuoka
  • Year and Date: 2015-11-22
  • Int'l Joint Research
• [Presentation] Dependence of effective interaction between macroanions in electrolyte solution on valence of co-ions (2015)
  • Author(s): Takumi Yamashita, Ryo Akiyama
  • Organizer: The 4th International Symposium “Dynamical Ordering of Biomolecular Systems for creation of integrated functions”(新学術領域研究『動的秩序と機能』第4回国際シンポジウム)
  • Place of Presentation: Fukuoka
  • Year and Date: 2015-11-22
  • Int'l Joint Research
• [Presentation] 電解質溶液内におけるマクロアニオン凝集の相図の計算 (2015)
  • Author(s): 澤山拓斗、秋山良
  • Organizer: 第38回溶液化学シンポジウム
  • Place of Presentation: 高知
  • Year and Date: 2015-10-21
• [Presentation] 電解質溶液中のマクロアニオン間実効相互作用に同符号イオンの価数が与える効果 (2015)
  • Author(s): 山下拓海、秋山良
  • Organizer: 第38回溶液化学シンポジウム
  • Place of Presentation: 高知
  • Year and Date: 2015-10-21
• [Presentation] Spatiotemporal dynamic ordering regulated by ATP hydrolysis and effective attraction between negatively charged sites in a biofluid, International (2015)
  • Author(s): Ryo Akiyama
  • Organizer: The 53rd Annual Meeting of the Biophysical Society of Japan, Formation of spatiotemporal dynamic ordering mediated by ATP hydrolysis (新学術 領域研究『動的秩序と機能』共催シンポジウム)
  • Place of Presentation: 金沢
  • Year and Date: 2015-09-13
  • Invited
• [Presentation] Aggregation behavior of macroanions immersed in electrolyte solution (2015)
  • Author(s): Takuto Sawayama, Ryo Akiyama
  • Organizer: 第53回日本生物物理学会年会
  • Place of Presentation: 金沢
  • Year and Date: 2015-09-13
• [Presentation] Effects of Preferential Solvation on Partial Molar Enthalpies in Binary Mixture Systems: Molecular Simulation Study (2015)
  • Author(s): Yuichi Kawabata, Ryo Akiyama
  • Organizer: 第53回日本生物物理学会年会
  • Place of Presentation: 金沢
  • Year and Date: 2015-09-13
• [Presentation] マクロアニオン間相互作用に対する同符号小イオンの価数依存性 (2015)
  • Author(s): 山下拓海、秋山良
  • Organizer: 第66回コロイドおよび界面化学討論会
  • Place of Presentation: 鹿児島
  • Year and Date: 2015-09-11
• [Presentation] Phase behavior of Acidic Protein electrolyte solution: Theoretical approach with a simple model (2015)
  • Author(s): Ryo Akiyama, Takuto Sawayama
  • Organizer: 2015 International Conference of Colloids and Interface Science
  • Place of Presentation: Taipei
  • Year and Date: 2015-07-21
  • Int'l Joint Research
• [Presentation] Effects of Co-ions with Different Valences on Effective Interaction between Macroanions in an Electrolyte Solution (2015)
  • Author(s): Takumi Yamashita, Ryo Akiyama
  • Organizer: 2015 International Conference of Colloids and Interface Science
  • Place of Presentation: Taipei
  • Year and Date: 2015-07-21
  • Int'l Joint Research
• [Presentation] Energy Conversion Efficiency of Solvation Motor driven by a Reaction on the Motor Surface (2015)
  • Author(s): Ken Tokunaga, Ryo Akiyama
  • Organizer: The 9th Mini Symposium on Liquids
  • Place of Presentation: Fukuoka
  • Year and Date: 2015-07-04
• [Presentation] Solute Size Dependence of Preferential Interaction in Hard-Sphere Mixture (2015)
  • Author(s): Yuichi Kawabata, Ryo Akiyama
  • Organizer: The 9th Mini Symposium on Liquids
  • Place of Presentation: Fukuoka
  • Year and Date: 2015-07-04
• [Presentation] Dependence of Effective Potential of Mean Force between Negatively Charged Colloidal Particles Immersed in an Electrolyte Solution on Charge of Small Anion (2015)
  • Author(s): Takumi Yamashita, Ryo Akiyama
  • Organizer: The 9th Mini Symposium on Liquids
  • Place of Presentation: Fukuoka
  • Year and Date: 2015-07-04
• [Presentation] Aggregation behavior of macroanions in an electrolyte solutio (2015)
  • Author(s): Takuto Sawayama, Ryo Akiyama
  • Organizer: The 9th Mini Symposium on Liquids
  • Place of Presentation: Fukuoka
  • Year and Date: 2015-07-04
• [Presentation] 静電相互作用による巨大分子構造形成とイオン交換による制御 (2015)
  • Author(s): 秋山良
  • Organizer: 日本化学会第９５春季年会『特別企画』水溶液における静電的相互作用の本質を探る
  • Place of Presentation: 日本大学 理工学部船橋キャンパス／薬学部、船橋
  • Year and Date: 2015-03-26
  • Invited
• [Presentation] 同符号電荷間の引力とアクチンの会合挙動 (2014)
  • Author(s): 秋山良
  • Organizer: 茨城大学理学部物理学科セミナー
  • Place of Presentation: 茨城大学、水戸
  • Year and Date: 2014-11-18
  • Invited
• [Presentation] Association of Actin Monomers and Effective Attraction between Like-Charged Colloidal Particles Mediated by Multivalent Cations (2014)
  • Author(s): Ryo Akiyama
  • Organizer: 第５２回日本生物物理学会念会 シンポジウム『生体分子機械の動作機構を周りの水から眺めてみる』
  • Place of Presentation: 札幌コンベンションセンター、札幌
  • Year and Date: 2014-09-26
  • Invited
• [Presentation] Interaction between like-charged particles and attractive patches on like-charged proteins (2014)
  • Author(s): Shingo Fujihara, Akira Yoshimori, Takuto Sawayama and *Ryo Akiyama
  • Organizer: International of Statistical Mechanics of Molecular Liquid on Soft Matter
  • Place of Presentation: Kasetsart University, Bangkok, Tailand
  • Year and Date: 2014-09-15
  • Invited
• [Presentation] 多価カチオンによって媒介される 同符号アニオン間実効引力と秩序構造 (2014)
  • Author(s): 秋山良
  • Organizer: アニオンの科学研究会
  • Place of Presentation: 東京工業大学 大岡山キャンパス
  • Year and Date: 2014-09-06
  • Invited
• [Book] エントロピーからはじめる熱力学 (2016)
  • Author(s): 安池智一、秋山良
  • Total Pages: 300
  • Publisher: 放送大学教育振興会