| Project/Area Number |
26220807
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| Research Category |
Grant-in-Aid for Scientific Research (S)
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| Allocation Type | Single-year Grants |
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| Research Field |
Bio-related chemistry
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| Research Institution | University of Hyogo (2016-2018)
Institute of Physical and Chemical Research (2014-2015) |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
澤井 仁美 兵庫県立大学, 生命理学研究科, 助教 (50584851)
杉田 有治 国立研究開発法人理化学研究所, 開拓研究本部, 主任研究員 (80311190)
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| Research Collaborator |
SUGIMOTO Hiroshi
TOSHA Takehiko
NAKAMURA Hiro
HISANO Tamao
KUBO Minoru
YAGI Kiyoshi
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| Project Period (FY) |
2014-05-30 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥195,130,000 (Direct Cost: ¥150,100,000、Indirect Cost: ¥45,030,000)
Fiscal Year 2018: ¥27,300,000 (Direct Cost: ¥21,000,000、Indirect Cost: ¥6,300,000)
Fiscal Year 2017: ¥26,390,000 (Direct Cost: ¥20,300,000、Indirect Cost: ¥6,090,000)
Fiscal Year 2016: ¥26,390,000 (Direct Cost: ¥20,300,000、Indirect Cost: ¥6,090,000)
Fiscal Year 2015: ¥70,200,000 (Direct Cost: ¥54,000,000、Indirect Cost: ¥16,200,000)
Fiscal Year 2014: ¥44,850,000 (Direct Cost: ¥34,500,000、Indirect Cost: ¥10,350,000)
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| Keywords | 一酸化窒素 / 脱窒 / 一酸化窒素還元酵素 / 呼吸酵素 / 金属酵素 / 膜タンパク質 / 酵素反応 / 温室効果ガス / 分子進化 / 窒素循環 / 環境科学 |
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| Outline of Final Research Achievements |
Denitirification is a kind of anaerobic respiration of microorganism, in which nitrate and nitrite are converted into N2 through intermediate formation of cytotoxic nitric oxide NO （NO3-→NO2-→NO→N2O→N2）. In this study, we have studied nitric oxide reductases NOR, a key enzyme of the denitrification, which detoxifies NO as follows; 2NO + 2H+ + 2e- → N2O + H2O. We newly found that NOR, NO decomposing enzyme, makes a complex with the NO-generating enzyme, nitrite reductase for the rapid NO detoxification without diffusing NO into the cell. We characterized the catalytic reaction with the time-resolved techniques, and proposed the molecular mechanism of the NO detoxification by NOR. These proposals allowed us to discuss the molecular evolution of respiratory enzymes from anaerobic to aerobic system. We also characterized the structural and functional changes of NORs of pathogens upon inhibitor binding.
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| Academic Significance and Societal Importance of the Research Achievements |
脱窒は地球上の窒素循環において重要な生物学的プロセスであり、その際に生成する亜酸化窒素（N2O）は温室効果ガスならびにオゾン層破壊ガスであり、その生成の約７割は、NOR反応（2NO + 2H+ + 2e- → N2O + H2O）による。この観点から、NORによるN2O産生の分子科学研究の成果は重要である（環境化学）。NORは生物の呼吸の祖先型酵素であり、酸素を使わない呼吸（嫌気呼吸）から酸素を使った呼吸（好気呼吸）への分子進化への手がかりを得た（基礎生物学）。病原菌もその感染増殖に活用する為にNORを有することから、その阻害剤開発の基礎データを得た（医科学）。
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| Assessment Rating |
Verification Result (Rating)
A
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Assessment Rating |
Result (Rating)
A-: Progress in the research is steadily towards the initial goal. However, further efforts are necessary as a part of the research progress is delayed.
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