Identification and Functional Analysis of Stimuli-responsive Chemical Species during Enzyme Reaction

2016 Fiscal Year Final Research Report

• Project Area: Stimuli-responsive Chemical Species for the Creation of Functional Molecules
• Project/Area Number: 24109017
• 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: Osaka University
• Principal Investigator: Inoue Tsuyohi 大阪大学, 工学研究科, 教授 (20263204)
• Co-Investigator(Kenkyū-buntansha): 中村 努 国立研究開発法人産業技術総合研究所, その他部局等, 研究員 (10357668) ; 松村 浩由 立命館大学, 生命科学部, 教授 (30324809)
• Project Period (FY): 2012-06-28 – 2017-03-31
• Keywords: チオレドキシンペルオキシダーゼ / 還元反応 / 酵素反応 / 反応中間体 / Ⅹ 線構造解析 / 中性子線解析 / Ⅹ線自由電子レーザー / SACLA

Outline of Final Research Achievements

Peroxiredoxin (Prx) has a Cys residue at its active site and shows the enzyme activity via S-OH intermediate containing hypervalent sulfur in the process of reducing hydrogen peroxide to water. For uncovering the presence of H atoms on the S atom by neutron analysis, we tried to obtain large crystals of Prx (ApPrx, PhPrx, TkPrx) derived from three types of hyperthermophilic archaea. None of them diffracted up to 3.0A resolution, and the presence of H atom on the S atom was not proved to date. However, the similar structure of S-OH intermediate existed in PhPrx, demonstrating the generality of the S-OH intermediate.

On the other hand, X-ray free electron laser is superior as a method to investigate stimuli-responsive chemical species. We have acquired a knowledge on structural change accompanying reduction upon X-ray irradiation was obtained from the completely oxidized form of nitrite reductase (NIR).

Free Research Field

構造生物学、基礎医学、免疫学