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O–H Activation by an Unexpected Ferryl Intermediate during Catalysis by 2-Hydroxyethylphosphonate Dioxygenase
- Source :
- Journal of the American Chemical Society
- Publication Year :
- 2017
- Publisher :
- American Chemical Society (ACS), 2017.
-
Abstract
- Activation of O–H bonds by inorganic metal-oxo complexes has been documented, but no cognate enzymatic process is known. Our mechanistic analysis of 2-hydroxyethylphosphonate dioxygenase (HEPD), which cleaves the C1–C2 bond of its substrate to afford hydroxymethylphosphonate on the biosynthetic pathway to the commercial herbicide phosphinothricin, uncovered an example of such an O–H-bond-cleavage event. Stopped-flow UV–visible absorption and freeze-quench Mössbauer experiments identified a transient iron(IV)-oxo (ferryl) complex. Maximal accumulation of the intermediate required both the presence of deuterium in the substrate and, importantly, the use of 2H2O as solvent. The ferryl complex forms and decays rapidly enough to be on the catalytic pathway. To account for these unanticipated results, a new mechanism that involves activation of an O–H bond by the ferryl complex is proposed. This mechanism accommodates all available data on the HEPD reaction.
- Subjects :
- 0301 basic medicine
2-hydroxyethylphosphonate
Stereochemistry
Molecular Conformation
Organophosphonates
010402 general chemistry
Photochemistry
01 natural sciences
Biochemistry
Article
Catalysis
Dioxygenases
Spectroscopy, Mossbauer
03 medical and health sciences
Colloid and Surface Chemistry
Dioxygenase
Mössbauer spectroscopy
Chemistry
Substrate (chemistry)
General Chemistry
Enzymatic process
0104 chemical sciences
Solvent
Kinetics
030104 developmental biology
Deuterium
Biocatalysis
Spectrophotometry, Ultraviolet
Iron Compounds
Subjects
Details
- ISSN :
- 15205126 and 00027863
- Volume :
- 139
- Database :
- OpenAIRE
- Journal :
- Journal of the American Chemical Society
- Accession number :
- edsair.doi.dedup.....7f8a43e34616397be2a519f4544389ae