Origin of Nitric Oxide Reduction Activity in Flavo-Diiron NO Reductase: Key Roles of the Second Coordination Sphere.
Angew Chem Int Ed Engl
; 58(12): 3795-3799, 2019 03 18.
Article
em En
| MEDLINE
| ID: mdl-30697895
ABSTRACT
The second coordination sphere constitutes a distinguishing factor in the active site to modulate enzymatic reactivity. To unravel the origin of NO-to-N2 O reduction activity of non-heme diiron enzymes, herein we report a strong second-coordination-sphere interaction between a conserved Tyr197 and the key iron-nitrosyl intermediate of Tm FDP (flavo-diiron protein), which leads to decreased reaction barriers towards N-N formation and N-O cleavage in NO reduction. This finding supports the direct coupling of diiron dinitrosyl as the N-N formation mode in our QM/MM modeling, and reconciles the mechanistic controversy of external reduction between FDPs and synthetic biomimetics of the iron-nitrosyls. This work highlights the application of QM/MM 57 Fe Mössbauer modeling in elucidating the structural features of not only first, but also second coordination spheres of the key transient species involved in NO/O2 activation by non-heme diiron enzymes.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oxirredutases
/
Óxido Nítrico
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Angew Chem Int Ed Engl
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
China