Detection of Water Molecules on the Radical Transfer Pathway of Ribonucleotide Reductase by 17O Electron–Nuclear Double Resonance Spectroscopy
| Autor: | JoAnne Stubbe, Marina Bennati, Fabian Hecker |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Free Radicals
Electrons Oxygen Isotopes 010402 general chemistry Photochemistry 01 natural sciences Biochemistry Catalysis Electron Transport Electron transfer Colloid and Surface Chemistry Ribonucleotide Reductases Escherichia coli Molecule Hyperfine structure Density Functional Theory chemistry.chemical_classification Chemistry Communication Electron Spin Resonance Spectroscopy Water General Chemistry Resonance (chemistry) 0104 chemical sciences Ribonucleotide reductase Enzyme Electron nuclear double resonance spectroscopy Tyrosine Proton-coupled electron transfer |
| Zdroj: | Journal of the American Chemical Society The Journal of the American Chemical Society |
| ISSN: | 1520-5126 0002-7863 |
| DOI: | 10.1021/jacs.1c01359 |
| Popis: | The role of water in biological proton-coupled electron transfer (PCET) is emerging as a key for understanding mechanistic details at atomic resolution. Here we demonstrate 17O high-frequency electron–nuclear double resonance (ENDOR) in conjunction with H217O-labeled protein buffer to establish the presence of ordered water molecules at three radical intermediates in an active enzyme complex, the α2β2E. coli ribonucleotide reductase. Our data give unambiguous evidence that all three, individually trapped, intermediates are hyperfine coupled to one water molecule with Tyr-O···17O distances in the range 2.8–3.1 Å. The availability of this structural information will allow for quantitative models of PCET in this prototype enzyme. The results also provide a spectroscopic signature for water H-bonded to a tyrosyl radical. |
| Databáze: | OpenAIRE |
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