Volume 22, No.2 Pages 172 - 173
3. SPring-8/SACLA通信／SPring-8/SACLA COMMUNICATIONS
2013B期 採択長期利用課題の事後評価について – 1 –
Post-Project Review of Long-term Proposals Starting in 2013B -1-
2013B期に採択された長期利用課題について、2016A期に3年間の実施期間が終了したことを受け、第59回SPring-8利用研究課題審査委員会長期利用分科会（2016年12月13日開催）において、事後評価が行われました。
事後評価は、長期利用分科会が実験責任者に対しヒアリングを行った後、評価を行うという形式で実施し、SPring-8利用研究課題審査委員会で評価結果を取りまとめました。以下に対象となる長期利用課題2課題の評価結果を示します。研究内容については本誌104ページの「最近の研究から」に実験責任者による紹介記事を掲載しています。
なお、2013B期に採択された長期利用課題3課題のうち残り1課題の評価結果は「SPring-8/SACLA利用者情報」Vol.22 No.4（2017年11月号）に掲載する予定です。
| 課題名 | Application Development of Nuclear Resonance Vibrational Spectroscopy (NRVS) and Synchrotron Mössbauer Spectroscopy of Multinuclear Iron Proteins |
| 実験責任者（所属） | Stephen Cramer (University of California, Davis) |
| 採択時課題番号 | 2013B0103 |
| ビームライン | BL09XU |
| 利用期間／配分総シフト | 2013B～2016A／99シフト |
［評価結果］
The principal investigator developed the technique of NRVS (Nuclear Resonance Vibrational Spectroscopy) to study vibrational modes of an iron atom in proteins. His group focused on Fe-S proteins in this project. They worked on intermediate states in enzymatic reactions of hydrogenase and nitrogenase which play important roles in hydrogen catalysis and nitrogen fixation, respectively. DFT models were used to analyze the NRVS spectra to discuss the mechanisms of enzymatic reactions. This is undoubtedly a leading-edge biochemistry as shown by more than ten publications since 2013 in high-profile journals such as J. Am. Chem. Soc., Angew. Chem. Int. Ed., and Nature Comm.. Thus, the committee judges that this project was completed successfully. There are some unresolved technical issues in the experimental techniques, which should be considered in the next Long-Term project.
［成果リスト］
（査読付き論文）
[1] SPring-8 publication ID = 27050
H. Wang et al.: "A Practical Guide for Nuclear Resonance Vibrational Spectroscopy (NRVS) of Biochemical Samples and Model Compounds" Methods in Molecular Biology 1122 (2014) 125-137.
[2] SPring-8 publication ID = 27816
L. Lars et al.: "Nuclear Resonance Vibrational Spectroscopy Reveals the FeS Cluster Composition and Active Site Vibrational Properties of an O2-tolerant NAD+-reducing [NiFe] Hydrogenase" Chemical Science 6 (2015) 1055-1060.
[3] SPring-8 publication ID = 28326
A. Scott et al.: "Structural Characterization of CO-Inhibited Mo-Nitrogenase by Combined Application of Nuclear Resonance Vibrational Spectroscopy, Extended X-ray Absorption Fine Structure, and Density Functional Theory: New Insights into the Effects of CO Binding and the Role of the Interstitial Atom" Journal of American Chemical Society 136 (2014) 15942-15954.
[4] SPring-8 publication ID = 32563
M. Maiuri et al.: "Low Frequency Dynamics of the Nitrogenase MoFe Protein via Femtosecond Pump Probe Spectroscopy－Observation of a Candidate Promoting Vibration" Journal of Inorganic Biochemistry 153 (2015) 128-135.
[5] SPring-8 publication ID = 32565
P. Serrano et al.: "Nitrosylation of Nitric-Oxide-Sensing Regulatory Proteins Containing [4Fe-4S] Clusters Gives Rise to Multiple Iron–Nitrosyl Complexes" Angewandte Chemie International Edition 55 (2016) 14575-14579.
[6] SPring-8 publication ID = 32566
H. Ogata et al.: "Hydride Bridge in [NiFe]-hydrogenase Observed by Nuclear Resonance Vibrational Spectroscopy" Nature Cimmunications 6 (2015) 7890.
[7] SPring-8 publication ID = 32619
L. Gee et al.: "Docking and Migration of Carbon Monoxide in Nitrogenase: The Case for Gated Pockets from IR Spectroscopy and Molecular Dynamics" Biochemistry 54 (2015) 3314-3319.
[8] SPring-8 publication ID = 33468
L. Gee et al.: "Synchrotron-based Nickel Mössbauer Spectroscopy" Inorganic chemistry 55 (2016) 6866-6872.
| 課題名 | NRVS of mononuclear and binuclear non-heme iron enzyme intermediates and related model complexes |
| 実験責任者（所属） | Edward Solomon (Stanford University) |
| 採択時課題番号 | 2013B0105 |
| ビームライン | BL09XU |
| 利用期間／配分総シフト | 2013B～2016A／135シフト |
［評価結果］
The Long-Term project aims at understanding the molecular mechanism of non-heme iron (NHFe) enzyme intermediates and related model complexes using nuclear resonance vibrational spectroscopy (NRVS) and density functional theory (DFT) calculations. In 2013B through 2016A oxygen-activated intermediates have been investigated, which include the selective halogenation of Fe(IV)=O NHFe intermediate, the low/high-spin chemistry of NHFe FeIII-OOH intermediates, the oxidative chemistry of extradiol dioxygenases, and the geometric and electronic structures of peroxy intermediates and high valent intermediates. The qualities of these results are high because of its unique approach to the local structure around iron ions in biologically relevant materials.
Besides for the results, the Long-Term project also has contributed to the development of a new methodology for investigating molecular systems with iron atoms, based on a combination of NRVS experiment and DFT computation. The series of studies have shown that the NRVS data are well reproduced by experimentally-calibrated DFT calculations, indicating that the methodology can provide reliable information on the reaction coordinate for catalysis and other molecular systems.
Therefore, the committee evaluates the Long-Term project as a successful one, although their publications are delayed. The results should be published in major journals as early as possible.
［成果リスト］
（査読付き論文）
[1] SPring-8 publication ID = 32555
K. Sutherlin et al.: "Nuclear Resonance Vibrational Spectroscopic Definition of Peroxy Intermediates in Nonheme Iron Sites" Journal of American Chemical Society 138 (2016) 14294-14302.
[2] SPring-8 publication ID = 33479
E. Solomon et al.: "O2 Activation by Non-Heme Iron Enzymes" Biochemistry 55 (2016) 6363-6374.
[3] SPring-8 publication ID = 33480
K. Park and E. Solomon: "Modeling nuclear resonance vibrational spectroscopic data of binuclear nonheme iron enzymes using density functional theory" Canadian Journal of Chemistry 92 (2014) 975-978.
