還元系金属酵素の有機金属・クラスター化学

2010 Fiscal Year Annual Research Report

• Project/Area Number: 18GS0207
• Research Institution: Nagoya University
• Principal Investigator: 巽 和行 名古屋大学, 物質科学国際研究センター, 教授 (10155096)
• Co-Investigator(Kenkyū-buntansha): 吉澤 一成 九州大学, 先導物質化学研究所, 教授 (30273486)
• Keywords: 金属硫黄クラスター / ヒドロゲナーゼ / ニトロゲナーゼ / 還元系金属酵素 / 小分子活性化 / アセチルCoA合成酵素 / COデヒドロゲナーゼ / 有機金属化学

Research Abstract

構造が明らかにされている生体内の鉄-硫黄クラスターのうち、最も大きな無機骨格を持つものは、ニトロゲナーゼに存在するP-clusterであり、その骨格は8つの鉄と7つの硫黄から構成される。特異な幾何構造を有するP-clusterの性質や反応性を直接的に明らかにすべく、より精密なモデルを構築するとともに、合成したモデルクラスターの性質を明らかにした。
P-clusterの[Fe_8S_7]骨格は6つのチオラート(システイン)によってタンパク中に保持されているが、従来合成してきたP-clusterモデル1には4つのアミド配位子と2つのチオ尿素配位子が配位している。そこで、これらをチオラートに置換し、より正確な
P-clusterのモデル合成を目指した。クラスター1の無機骨格はチオールやチオラート塩の存在下で容易に分解することが分かったが、低温でサンドイッチ型鉄錯体(η^5-C_5H_5)Fe(C_6H_5S)を加える反応から、2つのチオ尿素配位子がチオラートに置換された[Fe_8S_7]クラスターが得られ、続いて非常に嵩高いチオールを作用させることにより、計4つのチオラート配位子を導入した[Fe_8S_7]クラスターを合成することに成功した。
合成した一連のクラスターの酸化状態は、全てFe(II)_6Fe(III)_2であり、これは酸化型P-cluster(P^<OX>)に対応する。また電気化学測定の結果、一連のクラスターは準可逆な2段階の1電子還元を経て還元型(P^N)に対応するFe(II)_8状態になることが分かった。つまり合成したクラスターは、P-clusterの重要な機能と考えられているP^N⇔P^<OX>の可逆な2電子酸化還元を再現する。また、[Fe_8S_7]骨格に結合した配位子と酸化還元電位の関係から、アミド配位子がチオラート配位子よりも鉄に強く電子供与して高酸化状態を安定化することも明らかになった。

Research Products

• [Journal Article] Dihydrogen activation by sulfido-bridged dinuclear Ru/Ge complexes : insight into the [NiFe] hydrogenase unready state (2011)
  • Author(s): Matsumoto, T.; Itakura, N.; Nakaya, Y.; Tatsumi, K.
  • Journal Title: Chem.Commun. Volume: 47 Pages: 1030-1032
  • Peer Reviewed
• [Journal Article] Thiolate-Bridged Iron-Nickel Models for the Active Site of [NiFe] Hydrogenase (2011)
  • Author(s): Ohki, Y.; Tatsumi, K.
  • Journal Title: Eur.J.Inorg.Chem. Volume: 31 Pages: 973-985
  • Peer Reviewed
• [Journal Article] Cooperative Catalytic Activation of Si-H Bonds by a Polar Ru-S Bond : Regioselective Low-Temperature C-H Silylation of Indoles under Neutral Conditions by a Friedel-Crafts Mechanism (2011)
  • Author(s): Klare, H.F.T.; Oestreich, M.; Ito, J.; Nishiyama, H.; Ohki, Y.; Tatsumi, K.
  • Journal Title: J.Am.Chem.Soc. Volume: 133 Pages: 3312-3315
  • Peer Reviewed
• [Journal Article] Synthesis and Reactions of Coordinatively Unsaturated Half-Sandwich Rhodium and Iridium Complexes Having a 2,6-Dimesitylbenzenethiolate Ligand (2010)
  • Author(s): Sakamoto, M.; Ohki, Y.; Tatsumi, K.
  • Journal Title: Organometallics Volume: 29 Pages: 1761-7770
  • Peer Reviewed
• [Journal Article] Dodecanuclear-Ellipse and Decanuclear-Wheel Nickel(II) Thiolato Clusters with Efficient Femtosecond Nonlinear Absorption (2010)
  • Author(s): Zhang, C.; Matsumoto, T.; Samoc, M.; Petrie, S.; Meng, S.; Corkery, T.C.; Stranger, R.; Zhang, J.; Humphrey, M.G.; Tatsumi, K.
  • Journal Title: Angew.Chem.Int.Ed. Volume: 49 Pages: 4209-4212
  • Peer Reviewed
• [Journal Article] C-H Activation/Borylation of Furans and Thiophenes Catalyzed by a Half-Sandwich Iron N-Heterocyclic Carbene Complex (2010)
  • Author(s): Hatanaka, T.; Ohki, Y.; Tatsumi, K.
  • Journal Title: Chem.Asian J. Volume: 5 Pages: 1657-1666
  • Peer Reviewed
• [Journal Article] Synthesis of Coordinatively Unsaturated Mesityliron Thiolate Complexes and Their Reactions with Elemental Sulfur (2010)
  • Author(s): Hashimoto, T.; Ohki, Y.; Tatsumi, K.
  • Journal Title: Inorg.Chem. Volume: 49 Pages: 6102-6109
  • Peer Reviewed
• [Journal Article] An Iron(II) Carbonyl Thiolato Complex Bearing 2-Methoxy-Pyridine : A Structural Model of the Active Site of [Fe] Hydrogenase (2010)
  • Author(s): Tanino, S.; Ohki, Y.; Tatsumi, K
  • Journal Title: Chem.Asian J. Volume: 5 Pages: 1962-1964
  • Peer Reviewed
• [Journal Article] Exploring the Limits of Frustrated Lewis Pair Chemistry with Alkynes : Detection of a System that Favors 1,1-Carboboration over Cooperative 1,2-P/B-Addition (2010)
  • Author(s): Chen, C.; Eweiner, F.; Wibbeling, B.; Frchlich, R.; Senda, S.; Ohki, Y.; Tatsumi, K.; Grimme, S.; Kehr, G.; Erker, G.
  • Journal Title: Chem.Asian J. Volume: 5 Pages: 2199-2208
  • Peer Reviewed
• [Journal Article] Monomeric Iron(II) Complexes Having Two Sterically Hindered Arylthiolates (2010)
  • Author(s): Ohki, Y.; Ohta, S.; Tatsumi, K.
  • Journal Title: Inorg.Synth. Volume: 35 Pages: 137-143
  • Peer Reviewed
• [Journal Article] Coordination of Coenzyme M and Its Derivatives on Ni^<II> (tetraazacycle) Complexes : A Model for the Active Site of Methyl Coenzyme M Reductase (2010)
  • Author(s): Nishigaki, J.; Matsumoto, T.; Tatsumi, K.
  • Journal Title: Eur.J.Inorg.Chem. Volume: 30 Pages: 5011-5017
  • Peer Reviewed
• [Presentation] Chemical and Biological Synthesis of Iron-Sulfide Clusters by Tinker-Toy Construction or by Self-Assembly (2011)
  • Author(s): Kazuyuki Tatsumi
  • Organizer: International Symposium on Chemistry of Reductases IV
  • Place of Presentation: Nagoya, Japan
  • Year and Date: 20110120-20110121
• [Presentation] Chemistry of Reductase (2011)
  • Author(s): 巽和行
  • Organizer: 分子研研究会「金属錯体の機能化の現状と将来展望」
  • Place of Presentation: 岡崎
  • Year and Date: 20110108-20110109
• [Presentation] 還元系金属酵素の化学-自然に学ぶ (2011)
  • Author(s): 巽和行
  • Organizer: The 5^<th> Waseda GCOE International Symposium on "Practical Chemical Wisdom"「化学知をめぐって」
  • Place of Presentation: 早稲田大学
  • Year and Date: 2011-01-13
• [Presentation] Thiolate-bridged Dinuclear Fe(CO)_x(CN)_y-Ni Complexes (x,y=3,0;2,2;1,2) Modelling the Active Site of [NiFe] Hydrogenase (2010)
  • Author(s): Kazuyuki Tatsumi, Yasuhiro Ohki, Zilong Li, Soichiro Tanino, Kazunari Yasumura, Masaru Ando, Satoko Shimokata
  • Organizer: Pacifichem2010
  • Place of Presentation: Hawaii, USA
  • Year and Date: 20101215-20101220
• [Presentation] Activation of Small Molecules Promoted by Coordinatively Unsaturated Half-sandwich Rhodium and Iridium Complexes of 2,6-Dimesitylphenyl Thiolate (2010)
  • Author(s): Kazuyuki Tatsumi, Mayumi Sakamoto, Yasuhiro Ohki
  • Organizer: Pacifichem2010
  • Place of Presentation: Hawaii, USA
  • Year and Date: 20101215-20101220
• [Presentation] Dinuclear Nickel Complexes Modeling of the Active Site of Acetyl CoA Synthase : A Mechanistic Insight (2010)
  • Author(s): Tsuyoshi Matsumoto, Mikinao Ito, Kazuyuki Tatsumi
  • Organizer: Pacifichem2010
  • Place of Presentation: Hawaii USA
  • Year and Date: 20101215-20101220
• [Presentation] Synthesis of [Fe_8S_7] Clusters Analogous to the Metal-Sulfur Clusters in Nitrogenase (2010)
  • Author(s): Yasuhiro Ohki, Kazuyuki Tatsumi
  • Organizer: Pacifichem2010
  • Place of Presentation: Hawaii USA
  • Year and Date: 20101215-20101220
• [Presentation] Structural Models of the [NiFe] Hydrogenase Activge Site (2010)
  • Author(s): Kazuyuki Tatsumi
  • Organizer: 5^<th> Asian Biological Inorganic Chemistry Conference
  • Place of Presentation: Kaohsiung, Taiwan
  • Year and Date: 20101102-20101105
• [Presentation] New Synthetic Routes to Fe-S Clusters-Challenge to Modeling the Active Sites of Reductases (2010)
  • Author(s): Kazuyuki Tatsumi
  • Organizer: 11^<th> Eurasia Conference on Chemical Sciences
  • Place of Presentation: The Dead Sea, Jordan
  • Year and Date: 20101006-20101010
• [Presentation] Recent Progress in the Synthesis of Fe/S abd Fe/Mo/S Clusters-Challenge to Model the Active Sites of Nitrogenase- (2010)
  • Author(s): Kazuyuki Tatsumi
  • Organizer: 24^<th> Latin American Chemistry Congress
  • Place of Presentation: Cartagena, Colombia
  • Year and Date: 20100927-20101001
• [Presentation] Reductive Fusion of Two [Fe_4S_4] Clusters into an [Fe_8S_7] Core of Nitrogenase P-Cluster (2010)
  • Author(s): Yasuhiro Ohki, Norihiro Yamada, Kazuki Tanifuji, Kazuyuki Tatsumi
  • Organizer: 60th Anniversary Conference on Coordination Chemistry in Osaka
  • Place of Presentation: Osaka, Japan
  • Year and Date: 20100927-20100930
• [Presentation] Chemistry of Reductases (2010)
  • Author(s): Kazuyuki Tatsumi
  • Organizer: Frontier of Chemical Research, Texas A&M University
  • Place of Presentation: Texas, USA
  • Year and Date: 20100920-20100922
• [Presentation] Recent Progress in the Synthesis of Fe-S Clusters relevant to the Active Sites of Reductases (2010)
  • Author(s): Kazuyuki Tatsumi, Yasuhiro Ohki
  • Organizer: 8^<th> China-Japan Joint Symposium on Metal Cluster Compounds
  • Place of Presentation: Xian, China
  • Year and Date: 20100810-20100814
• [Presentation] Organometallic Routes to Fe-S Clusters-Challenge to Model the Active Sites of Reductases- (2010)
  • Author(s): Kazuyuki Tatsumi, Yasuhiro Ohki
  • Organizer: 24^<th> International Conference on Organometallic Chemistry
  • Place of Presentation: Taipei, Taiwan
  • Year and Date: 20100718-20100723
• [Presentation] Thiolate-bridged Dinuclear Fe(CO)_3-Ni, Fe(CO)_2(CN)_2-Ni, and Fe(CO)(CN)_2-Ni" Complexes as Structural Models of the [NiFe] Hydrogenase Active Site (2010)
  • Author(s): Kazuyuki Tatsumi, Yasuhiro Ohki, Zilong Li, Soichiro Tanino
  • Organizer: 9^<th> International Hydrogenase Conference
  • Place of Presentation: Uppsala, Sweden
  • Year and Date: 20100627-20100702
• [Presentation] C-H Bond Activation and Borylation of Heteroarenes Promoted by Half-Sandwich Iron Complexes (2010)
  • Author(s): Yasuhiro Ohki
  • Organizer: The 9th Joint Seminar between Nagoya University and University of Munster
  • Place of Presentation: Nagoya University
  • Year and Date: 20100524-20100525
• [Presentation] Model Chemistry of Acetyl-CoA Synthase and Methyl-CoM Reductase (2010)
  • Author(s): Tsuyoshi Matsumoto
  • Organizer: Bioinorganic Seminar at Max-Planck Institute
  • Place of Presentation: Marburg, Germany
  • Year and Date: 2010-07-05
• [Presentation] 還元系金属酵素の有機金属化学 (2010)
  • Author(s): 巽和行
  • Organizer: 有機合成化学協会講習会
  • Place of Presentation: 東京
  • Year and Date: 2010-06-23
• [Remarks]
  • URL: http://www.chem.nagoya-u.ac.jp/~ic/grant/index.html