| Autor: |
Takeshi Murakawa, Mamoru Suzuki, Kenji Fukui, Tetsuya Masuda, Michihiro Sugahara, Kensuke Tono, Tomoyuki Tanaka, So Iwata, Eriko Nango, Takato Yano, Katsuyuki Tanizawa, Toshihide Okajima |
| Rok vydání: |
2022 |
| Předmět: |
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| Zdroj: |
Acta crystallographica. Section D, Structural biology. 78(Pt 12) |
| ISSN: |
2059-7983 |
| Popis: |
The mechanisms by which enzymes promote catalytic reactions efficiently through their structural changes remain to be fully elucidated. Recent progress in serial femtosecond X-ray crystallography (SFX) using X-ray free-electron lasers (XFELs) has made it possible to address these issues. In particular, mix-and-inject serial crystallography (MISC) is promising for the direct observation of structural changes associated with ongoing enzymic reactions. In this study, SFX measurements using a liquid-jet system were performed on microcrystals of bacterial copper amine oxidase anaerobically premixed with a substrate amine solution. The structure determined at 1.94 Å resolution indicated that the peptidyl quinone cofactor is in equilibrium between the aminoresorcinol and semiquinone radical intermediates, which accumulate only under anaerobic single-turnover conditions. These results show that anaerobic conditions were well maintained throughout the liquid-jet SFX measurements, preventing the catalytic intermediates from reacting with dioxygen. These results also provide a necessary framework for performing time-resolved MISC to study enzymic reaction mechanisms under anaerobic conditions. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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