特異なクラスター活性中心をもつ酸化還元金属酵素の生物無機化学

2012 Fiscal Year Annual Research Report

• Project/Area Number: 23000007
• Research Institution: Nagoya University
• Principal Investigator: 巽 和行 名古屋大学, 学内共同利用施設等, 教授 (10155096)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: ニトロゲナーゼ / 酸化還元酵素 / クラスター / ヒドロゲナーゼ / COデヒドロゲナーゼ

Outline of Annual Research Achievements

本年度に得られた主要な成果について以下に記載する。
(1) ニトロゲナーゼFeMo-cofactorのモデルとなる、酸素原子を内包した[Fe8S6O]型クラスターの合成と構造：FeMo-cofactorの基本骨格に類似した[Fe8S7]クラスターの合成反応を発展させ、少量の水存在下での反応から、クラスター中心に酸素原子を持つ新規[Fe8S6O]クラスターを合成した。中心酸素原子は、周囲にある6つの鉄原子のうち4つと結合する一方、残る2つの配位不飽和な鉄原子はチオラート配位子の芳香環と弱く相互作用しており、この結果はFeMo-cofactorの鉄が外部基質を捕捉する機構を考察する有用な知見である。
(2) 光化学系II酸素発生中心(OEC)を模倣するMn/O、Mn/OH、およびMn/Ca/Oクラスターの合成：マンガンアミド錯体を前駆体とし、かさ高いアルコキシド／シロキシドを補助配位子に用いる我々独自のクラスター自己集積反応を開拓し、その結果Mn/O, Mn/OH, Mn/Ca/Oクラスターの合成に成功した。特に、融合型不完全キュバン構造のMn4(OH)2(OSiiPr3)6クラスターとカルシウム錯体の反応によって得られたMn4Ca2(O)2 (OSiiPr3)8は、OECの構造に関連して興味深い。
(3) ジアミドジチオラート型四座配位子mbeaを利用した、アセチルCoA合成酵素の反応中間体モデル合成：アセチルCoA合成酵素に存在するニッケル二核錯体のモデルとして、実際の酵素に近いテトラアニオン性N2S2配位子mbeaを導入した二核ニッケルモデル錯体の合成を検討した。末端ニッケル上にメチル基とチオラートを併せ持つ錯体の合成に成功し、X線構造解析でその構造が酵素活性中心に極めて類似していることを明らかにした。

Current Status of Research Progress

1: Research has progressed more than it was originally planned.

Reason

今年度は当初予定していた以上の進捗があった。中心にO原子が導入されたニトロゲナーゼFeMo-cofactorの構造モデルの合成に成功するだけでなく、その高精度の構造解析が達成させ、骨格中心の原子がニトロゲナーゼ骨格の構造変化に与える影響が明らかになり、同時に活性中心に基質が配位する機構についても示唆が得られた。光化学系II酸素発生中心のモデルとなるMn/Oクラスターの合成も予定以上のペースで進捗し、次年度以降に実施予定であったCaの導入によるMn/Ca/Oクラスターの合成にも着手した。またアセチルCoA合成酵素モデル研究では、中間体のモデルとなるニッケル二核錯体の合成に成功し、反応機構解明に向けて進捗している。これらの課題に加え、生化学者との共同研究として、金属硫黄クラスターのニトロゲナーゼへの導入を行い、基質還元活性を評価も予定以上に進捗し、[NiFe]ヒドロゲナーゼ、[4Fe-4S]クラスターのモデル合成も同時に進めている。

Strategy for Future Research Activity

研究は予定していた以上に進捗し、予定を前倒しして検討を進めて行く。FeMo-cofactor、ヒドロゲナーゼ、光化学系II酸素発生中心、アセチルCoA合成酵素などのモデル研究を進める一方、生化学者との共同研究をさらに深化させ、ニトロゲナーゼのアポタンパクを利用した研究に加え、ニトロゲナーゼ類似構造をもつ酵素であるDPORを利用した人工還元酵素の構築に向けて研究を開始する予定である。

Research Products

• [Journal Article] An unexpectedly branched biosynthetic pathway for bacteriochlorophyll b capable of absorbing near-infrared light (2013)
  • Author(s): Tsukatani, Y., Yamamoto, H., Harada, J., Yoshitomi, T., Nomata, J., Kasahara, M., Mizoguchi, T., Fujita, Y. and Tamiaki, H
  • Journal Title: Sci. Rep Volume: 3 Pages: 1217
  • DOI: 10.1038/srep01217
  • Peer Reviewed
• [Journal Article] Coordination of Methyl Coenzyme M and Coenzyme M at Divalent and Trivalent Nickel Cyclams: Model Studies of the Methyl Coenzyme M Reductase Active Site (2012)
  • Author(s): J. Nishigaki, T. Matsumoto, and K. Tatsumi
  • Journal Title: Inorg. Chem Volume: 51 Pages: 3690-3697
  • DOI: 10.1021/ic202686x
  • Peer Reviewed
• [Journal Article] Tridentate Thiolate Ligands: Application to the Synthesis of the Site-Differentiated [4Fe-4S] Cluster having a Hydrosulfide Ligand at the Unique Iron Center (2012)
  • Author(s): T. Terada, T. Wakimoto, T. Nakamura, K. Hirabayashi, K. Tanaka, J. Li, T. Matsumoto, and K. Tatsumi
  • Journal Title: Chem. Asian J Volume: 7 Pages: 920-929
  • DOI: 10.1002/asia.201200039
  • Peer Reviewed
• [Journal Article] Naphthalene and Anthracene Complexes Sandwiched by Two Cp*Fe Fragments: Strong Electronic Coupling Between the FeI Centers (2012)
  • Author(s): T. Hatanaka, Y. Ohki, T. Kamachi, T. Nakayama, K. Yoshizawa, M. Katada, K. Tatsumi
  • Journal Title: Chem. Asian J Volume: 7 Pages: 1231-1242
  • DOI: 10.1002/asia.201101037
  • Peer Reviewed
• [Journal Article] Non-Centrosymmetric Coordination Polymer with a Highly Hindered Octahedral Copper Center Bridged by Mandelate (2012)
  • Author(s): M. Moriya, S. Tominaga, T.i Hashimoto, K. Tanifuji, T. Matsumoto, Y. Ohki, K. Tatsumi, J. Kaneshiro, Y. Uesu, W. Sakamoto, T. Yog
  • Journal Title: Inorg. Chem Volume: 51 Pages: 4689-4693
  • DOI: 10.1021/ic202669r
  • Peer Reviewed
• [Journal Article] Synthesis of Bis(N-heterocyclic carbene) Complexes of Iron(II) and Their Application in Hydrosilylation and Transfer Hydrogenation (2012)
  • Author(s): T. Hashimoto, S. Urban, R. Hoshino, Y. Ohki, K. Tatsumi, F. Glorius
  • Journal Title: Organometallics Volume: 31 Pages: 4474-4479
  • DOI: 10.1021/om300298q
  • Peer Reviewed
• [Journal Article] Model Studies of Methyl CoM Reductase: Methane Formation via CH3-S Bond Cleavage of Ni(I) Tetraazacyclic Complexes Having Intramolecular Methyl Sulfide Pendants (2012)
  • Author(s): J. Nishigaki, T. Matsumoto, and K. Tatsumi
  • Journal Title: Inorg. Chem Volume: 51 Pages: 5173-5187
  • DOI: 10.1021/ic300017k
  • Peer Reviewed
• [Journal Article] Base-Free Dehydrogenative Coupling of Enolizable Carbonyl Compounds with Silanes Involving Catalytic Generation of the Silicon Electrophile (2012)
  • Author(s): C. David F. Konigs, Hendrik F. T. Klare, Yasuhiro Ohki, Kazuyuki Tatsumi, Martin Oestreich
  • Journal Title: Org. Lett Volume: 14 Pages: 2842-2845
  • DOI: 10.1021/ol301089r
  • Peer Reviewed
• [Journal Article] An Iron(II) Complex of Diamine-Bridged Bis-N-Heterocyclic Carbene (2012)
  • Author(s): C. Grohmann, T. Hashimoto, R. Frohlich, Y. Ohki, K. Tatsumi, F. Glorius
  • Journal Title: Organometallics Volume: 31 Pages: 8047-8050
  • DOI: 10.1021/om300888q
  • Peer Reviewed
• [Journal Article] Formation of a Nitrogenase P-Cluster [Fe8S7] Core via Reductive Fusion of Two All-Ferric [Fe4S4] Clusters (2012)
  • Author(s): Y. Ohki, K. Tanifuji, N. Yamada, R. E. Cramer, and K. Tatsumi
  • Journal Title: Chem. Asian J Volume: 7 Pages: 2222-2224
  • DOI: 10.1002/asia.201200568
  • Peer Reviewed
• [Journal Article] A Nitrogenase Cluster Model [Fe8S6O] with an Oxygen Unsymmetrically Bridging two Proto-Fe4S3 Cubes: Relevancy to the Substrate-Binding Mode of the FeMo-cofactor (2012)
  • Author(s): S. Ohta, Y. Ohki, R. E. Cramer, and K. Tatsumi
  • Journal Title: Inorg. Chem Volume: 51 Pages: 11217-11219
  • DOI: 10.1021/ic301348f
  • Peer Reviewed
• [Presentation] Synthesis of Iron-Sulfur Clusters Relevant to Nitrogenase Active Sites -Flexible Nature of the Cluster Structures- (2013)
  • Author(s): K. Tatsumi
  • Organizer: Bioinorganic Chemistry Conference 2013, ZiNG Conferences
  • Place of Presentation: Barcelo(Lanzarote, Spain)
  • Year and Date: 2013-02-19 – 2013-02-22
  • Invited
• [Presentation] クラスター活性部位を持つ金属酵素：化学の挑戦 (2013)
  • Author(s): 巽 和行
  • Organizer: 化学の挑戦”、分子研研究会「生体配位化学の最前線と展望」
  • Place of Presentation: 分子科学研究所(岡崎,日本）
  • Year and Date: 2013-02-05 – 2013-02-06
  • Invited
• [Presentation] Flexible Nature of Iron-Sulfide Clusters Relevant to the Active Site of Nitrogenase (2012)
  • Author(s): K. Tatsumi
  • Organizer: 2nd International Conference of MEXT Project of Integrated research on Chemical Synthesis
  • Place of Presentation: Noyori Conference Hall(Nagoya, Japan)
  • Year and Date: 2012-12-10 – 2012-12-11
  • Invited
• [Presentation] Synthesis of Irin-Sulfide Clusters Relevant to Nitrogenase Active Sites -Flexible Nature of the Cluster Structures- (2012)
  • Author(s): K. Tatsumi
  • Organizer: Department Seminar, University of Alberta under Distinguished Asia Visitor Program
  • Place of Presentation: University of Alberta(Edmonton, Canada)
  • Year and Date: 2012-11-26 – 2012-11-26
  • Invited
• [Presentation] Chemistry of Oxidoreductases: Learning from nature for our Future Sustainable Society (2012)
  • Author(s): K. Tatsumi
  • Organizer: Chemical Institute of Canada Edmonton Section under Distinguished Asia Visitor Program
  • Place of Presentation: University of Alberta(Edmonton, Canada)
  • Year and Date: 2012-11-22 – 2012-11-22
  • Invited
• [Presentation] Flexible Nature of the Iron-Sulfide Clusters Relevant to the Active Sites of Reductases -What We Know and What We Do Not- (2012)
  • Author(s): K. Tatsumi
  • Organizer: Department Seminar, University of British Columbia under Distinguished Asia Visitor Program
  • Place of Presentation: University of British Columbia(Vancouver, Canada)
  • Year and Date: 2012-11-21 – 2012-11-21
  • Invited
• [Presentation] Active Site Model Synthesis of Acetyl CoA Synthase (2012)
  • Author(s): T. Matsumoto
  • Organizer: Seminar at the University of Delaware
  • Place of Presentation: University of Delaware(Delaware, USA)
  • Year and Date: 2012-11-01 – 2012-11-01
  • Invited
• [Presentation] Chemistry of Cluster Active Sites of Oxidoreductases -A Key to Realizing a Sustainable Society- (2012)
  • Author(s): K. Tatsumi
  • Organizer: 30th Latin American Chemistry Congress (LACC-2012)
  • Place of Presentation: Hotel Marriott CasaMagna Cancun Resort(Cancun, Mexico)
  • Year and Date: 2012-10-27 – 2012-10-31
  • Invited
• [Presentation] Half-Sandwich Iron Complexes for C-H Bond Activation and Borylation of Heteroarenes (2012)
  • Author(s): Y. Ohki
  • Organizer: Cambodian Malaysian Chemical Conference 2012
  • Place of Presentation: Angkor Century Resort Spa(Siem-Reap, Cambodia)
  • Year and Date: 2012-10-19 – 2012-10-20
  • Invited
• [Presentation] Half-Sandwich Iron Complexes for C-H Bond Activation and Borylation of Heteroarenes (2012)
  • Author(s): Y. Ohki
  • Organizer: 17th Malaysian Chemical Congress 2012
  • Place of Presentation: Putra World Trade Center(Kuala-Lumpur, Malaysia)
  • Year and Date: 2012-10-15 – 2012-10-17
  • Invited
• [Presentation] Model Studies of NiFe-Hydrogenase and Acetyl CoA Synthase (2012)
  • Author(s): T. Matsumoto
  • Organizer: Organimetallic Seminar at the University of Rochester
  • Place of Presentation: University of Rochester(Rochester, USA)
  • Year and Date: 2012-10-02 – 2012-10-02
  • Invited
• [Presentation] Chemistry of the Cluster Active Sites in Reductases -A Key to Realizing a Sustainable Society- (2012)
  • Author(s): K. Tatsumi
  • Organizer: Department Seminar, University of Coimbra
  • Place of Presentation: University of Coimbra(Coimbra, Portugal)
  • Year and Date: 2012-09-07 – 2012-09-07
  • Invited
• [Presentation] Structural Models of the [NiFe] Hydrogenase Active Site (2012)
  • Author(s): K. Tatsumi
  • Organizer: JOM Symposium at XXVth International Conference on Organmetallic Chemistry
  • Place of Presentation: Technical University of Lisbon (Lisbon, Portugal)
  • Year and Date: 2012-09-02 – 2012-09-07
  • Invited
• [Presentation] Iron-Sulfide Clusters Relevant to Nitrogenase Active Site -Flexible Nature of the Cluster Structures- (2012)
  • Author(s): K. Tatsumi
  • Organizer: 9th Japan-China Joint Symposium on Metal Cluster Compounds
  • Place of Presentation: Hilton Fukuoka Sea Hawk Hotel(Fukuoka, Japan)
  • Year and Date: 2012-08-01 – 2012-08-15
  • Invited
• [Presentation] Synthesis of the Cluster Active Sites of Reductases -A Key to Realizing a Sustainable Society- (2012)
  • Author(s): K. Tatsumi
  • Organizer: Department Seminar, RWTH Aachen University
  • Place of Presentation: Aachen University(Aachen, Germany)
  • Year and Date: 2012-06-28 – 2012-06-28
  • Invited
• [Presentation] Iron-Sulfur and Iron-Molybdenum-Sulfur Clusters Modeling the Active Site of Nitrogenase (2012)
  • Author(s): K. Tatsumi
  • Organizer: Russian Conference on Chemistry of Polynuclear and Cluster Compounds <Cluster-2012>
  • Place of Presentation: House of Scientists (Dom Uchonyh)（Novosibirsk, Russia）
  • Year and Date: 2012-06-17 – 2012-06-22
  • Invited
• [Presentation] Non-classical Iron-Sulfur Clusters: What We Know, and What We Do Not (2012)
  • Author(s): K. Tatsumi
  • Organizer: Gordon Research Conference “Iron-Sulfur Enzymes”
  • Place of Presentation: Mount Holyoke College(South Hadley, MA, USA )
  • Year and Date: 2012-06-10 – 2012-06-15
  • Invited
• [Presentation] ニトロゲナーゼ活性部位の人工構築を志向した鉄-硫黄クラスター合成反応 (2012)
  • Author(s): 大木靖弘
  • Organizer: 第３回統合物質シンポジウム
  • Place of Presentation: 九州大学西新プラザ（福岡,日本）
  • Year and Date: 2012-06-01 – 2012-06-02
  • Invited
• [Presentation] Chemistry of the Cluster Active Sites in Metalloenzymes -A Key to Realizing a Sustainable Society- (2012)
  • Author(s): K. Tatsumi
  • Organizer: 25th Annual Meeting of the Brazilian Chemical Society
  • Place of Presentation: Centro de Convencoes do Hotel Monte Real Resor(Sao Paulo, Brazil)
  • Year and Date: 2012-05-28 – 2012-05-31
  • Invited
• [Presentation] The Flexible Nature of Iron-Sulfide Clusters -Nitorgenase P-Cluster/FeMo-co Models- (2012)
  • Author(s): K. Tatsumi
  • Organizer: 13th IRTG Joint Symposium
  • Place of Presentation: Munster University(Munster, Germany)
  • Year and Date: 2012-05-07 – 2012-05-08
  • Invited
• [Presentation] Chemistry of the Cluster Active Sites in Metalloenzymes -A Key to Realizing a Sustainable Society - (2012)
  • Author(s): K. Tatsumi
  • Organizer: Department Seminar, University of Strasbourg
  • Place of Presentation: University of Strasbourg(Strasbourg, France)
  • Year and Date: 2012-05-03 – 2012-05-03
  • Invited