The neutron structure of urate oxidase resolves a long-standing mechanistic conundrum and reveals unexpected changes in protonation.
Urate oxidase transforms uric acid to 5-hydroxyisourate without the help of cofactors, but the catalytic mechanism has remained enigmatic, as the protonation state of the substrate could not be reliably deduced. We have determined the neutron structure of urate oxidase, providing unique information...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2014-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC3900588?pdf=render |
| _version_ | 1818851833796362240 |
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| author | Esko Oksanen Matthew P Blakeley Mohamed El-Hajji Ulf Ryde Monika Budayova-Spano |
| author_facet | Esko Oksanen Matthew P Blakeley Mohamed El-Hajji Ulf Ryde Monika Budayova-Spano |
| author_sort | Esko Oksanen |
| collection | DOAJ |
| description | Urate oxidase transforms uric acid to 5-hydroxyisourate without the help of cofactors, but the catalytic mechanism has remained enigmatic, as the protonation state of the substrate could not be reliably deduced. We have determined the neutron structure of urate oxidase, providing unique information on the proton positions. A neutron crystal structure inhibited by a chloride anion at 2.3 Å resolution shows that the substrate is in fact 8-hydroxyxanthine, the enol tautomer of urate. We have also determined the neutron structure of the complex with the inhibitor 8-azaxanthine at 1.9 Å resolution, showing the protonation states of the K10-T57-H256 catalytic triad. Together with X-ray data and quantum chemical calculations, these structures allow us to identify the site of the initial substrate protonation and elucidate why the enzyme is inhibited by a chloride anion. |
| first_indexed | 2024-12-19T07:11:19Z |
| format | Article |
| id | doaj.art-94796461279c4ae2939abff8fe751d7f |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-19T07:11:19Z |
| publishDate | 2014-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-94796461279c4ae2939abff8fe751d7f2022-12-21T20:31:10ZengPublic Library of Science (PLoS)PLoS ONE1932-62032014-01-0191e8665110.1371/journal.pone.0086651The neutron structure of urate oxidase resolves a long-standing mechanistic conundrum and reveals unexpected changes in protonation.Esko OksanenMatthew P BlakeleyMohamed El-HajjiUlf RydeMonika Budayova-SpanoUrate oxidase transforms uric acid to 5-hydroxyisourate without the help of cofactors, but the catalytic mechanism has remained enigmatic, as the protonation state of the substrate could not be reliably deduced. We have determined the neutron structure of urate oxidase, providing unique information on the proton positions. A neutron crystal structure inhibited by a chloride anion at 2.3 Å resolution shows that the substrate is in fact 8-hydroxyxanthine, the enol tautomer of urate. We have also determined the neutron structure of the complex with the inhibitor 8-azaxanthine at 1.9 Å resolution, showing the protonation states of the K10-T57-H256 catalytic triad. Together with X-ray data and quantum chemical calculations, these structures allow us to identify the site of the initial substrate protonation and elucidate why the enzyme is inhibited by a chloride anion.http://europepmc.org/articles/PMC3900588?pdf=render |
| spellingShingle | Esko Oksanen Matthew P Blakeley Mohamed El-Hajji Ulf Ryde Monika Budayova-Spano The neutron structure of urate oxidase resolves a long-standing mechanistic conundrum and reveals unexpected changes in protonation. PLoS ONE |
| title | The neutron structure of urate oxidase resolves a long-standing mechanistic conundrum and reveals unexpected changes in protonation. |
| title_full | The neutron structure of urate oxidase resolves a long-standing mechanistic conundrum and reveals unexpected changes in protonation. |
| title_fullStr | The neutron structure of urate oxidase resolves a long-standing mechanistic conundrum and reveals unexpected changes in protonation. |
| title_full_unstemmed | The neutron structure of urate oxidase resolves a long-standing mechanistic conundrum and reveals unexpected changes in protonation. |
| title_short | The neutron structure of urate oxidase resolves a long-standing mechanistic conundrum and reveals unexpected changes in protonation. |
| title_sort | neutron structure of urate oxidase resolves a long standing mechanistic conundrum and reveals unexpected changes in protonation |
| url | http://europepmc.org/articles/PMC3900588?pdf=render |
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