How cofactor-free oxygenases can overcome spin prohibition in substrates oxygenation by dioxygen
| Autor: | B.F. Minaev |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
010304 chemical physics
biology Superoxide General Physics and Astronomy Substrate (chemistry) Flavin group 010402 general chemistry Photochemistry 01 natural sciences Cofactor 0104 chemical sciences Paramagnetism chemistry.chemical_compound chemistry 0103 physical sciences biology.protein Molecule Reactivity (chemistry) Physical and Theoretical Chemistry Spin (physics) |
| Zdroj: | Chemical Physics. 521:61-68 |
| ISSN: | 0301-0104 |
| DOI: | 10.1016/j.chemphys.2019.01.021 |
| Popis: | Oxidases and oxygenases can activate the triplet ground state O2 molecule for the controlled chemical synthesis initiated by virtue of electron-transfer process which leads to dioxygen reduction. Typically they use organic cofactor or paramagnetic metal ion to initiate dioxygen activation and overcome spin prohibition for triplet O2 reactivity. A number of mono- and di-oxygenases are found recently which can operate even in the absence of any cofactor. Analysis of spin-orbit coupling in such enzymes helps to unravel some mechanistic puzzles and explains why aromatic substrate works instead cofactor. A general attribute of such enzymes, O2− radical, provides a good opportunity to induce internal magnetic perturbation and fulfill the spin flip as a common way to overcome spin prohibition for dioxygen activation. The driving force for spin flip – spin-orbit coupling inside superoxide ion – does not depend on the radical-pair partner; thus π-delocalized substrate can operate instead of flavin cofactor. |
| Databáze: | OpenAIRE |
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