Identification of Fe()-OH species as a catalytic intermediate in plant peroxidases at high HO concentration
The structural determinants underlying the instability of plant peroxidases toward H 2 O 2 are unknown. The reaction of the catalytically productive radical Fe( iv )&z.dbd;O species with excess H 2 O 2 generates a species named compound III , which is known to decay partitioning between ground s...
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| Published in | New journal of chemistry Vol. 46; no. 1; pp. 4579 - 4586 |
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| Main Authors | , , , , , , |
| Format | Journal Article |
| Published |
28.02.2022
|
| Online Access | Get full text |
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| Summary: | The structural determinants underlying the instability of plant peroxidases toward H
2
O
2
are unknown. The reaction of the catalytically productive radical Fe(
iv
)&z.dbd;O species with excess H
2
O
2
generates a species named compound
III
, which is known to decay partitioning between ground state restoration and inactivation following catalytical suicide kinetics. To elucidate the structural changes involved in compound
III
formation and decay, here we report the characterization of two plant peroxidases using catalytic and spectroscopic characterization. Resonance Raman and EPR characterizations reveal that the structure of compound
III
is more related to the hydroxyl form of other heme proteins and not to the peroxyferryl form as has been previously suggested.
The structure for compound
III
formed after exposure of plant heme peroxidases to excess H
2
O
2
seems to be a hydroxylated form, providing new evidence for understanding the structural basis of the substrate-induced suicidal behavior of these enzymes. |
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| Bibliography: | 10.1039/d1nj04837f Electronic supplementary information (ESI) available: Experimental methods and results; molecular structures and topological data. See DOI |
| ISSN: | 1144-0546 1369-9261 |
| DOI: | 10.1039/d1nj04837f |