Activation Thermodynamics and H/D Kinetic Isotope Effect of the Hox to HredH+ Transition in [FeFe] Hydrogenase.
J Am Chem Soc
; 139(37): 12879-12882, 2017 09 20.
Article
em En
| MEDLINE
| ID: mdl-28851216
ABSTRACT
Molecular complexes between CdSe nanocrystals and Clostridium acetobutylicum [FeFe] hydrogenase I (CaI) enabled light-driven control of electron transfer for spectroscopic detection of redox intermediates during catalytic proton reduction. Here we address the route of electron transfer from CdSeâCaI and activation thermodynamics of the initial step of proton reduction in CaI. The electron paramagnetic spectroscopy of illuminated CdSeCaI showed how the CaI accessory FeS cluster chain (F-clusters) functions in electron transfer with CdSe. The HoxâHredH+ reduction step measured by Fourier-transform infrared spectroscopy showed an enthalpy of activation of 19 kJ mol-1 and a â¼2.5-fold kinetic isotope effect. Overall, these results support electron injection from CdSe into CaI involving F-clusters, and that the HoxâHredH+ step of catalytic proton reduction in CaI proceeds by a proton-dependent process.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Termodinâmica
/
Compostos de Selênio
/
Compostos de Cádmio
/
Hidrogenase
/
Proteínas Ferro-Enxofre
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article