Excited-State Properties of Fully Reduced Flavins in Ferredoxin-NADP+ Oxidoreductase.
J Phys Chem Lett
; 14(4): 1096-1102, 2023 Feb 02.
Article
em En
| MEDLINE
| ID: mdl-36700861
ABSTRACT
The fully reduced flavin cofactor (FADred) in ferredoxin-NADP+ oxidoreductase (FNR) is a functional intermediate that displays different catalytic and steady-state spectral properties for enzymes from Bacillus subtilis (BsFNR), Chlorobaculum tepidum (CtFNR), and Rhodopseudomonas palustris (RpFNR). Using ultrafast spectroscopy, we reveal that at physiological pH, photoexcited FADred in BsFNR and RpFNR exhibits unprecedentedly fast decays (dominantly in 6 and 8 ps, respectively), whereas in CtFNR the decay is much slower (â¼400 ps), as in other flavoproteins. Correlating these observations with the protonation states of FADred and the dynamic properties of the protein environment, we conclude that the excited state of neutral FADred can be intrinsically short-lived even in proteins, contrasting with the well-documented behavior of the anionic form that systematically displays markedly increased excited-state lifetime upon binding to proteins. This work provides new insight into the photochemistry of fully reduced flavins, which are emerging as functional initial states in bioengineered photocatalysts.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Chlorobi
/
Ferredoxinas
Idioma:
En
Revista:
J Phys Chem Lett
Ano de publicação:
2023
Tipo de documento:
Article