Detection of Water Molecules on the Radical Transfer Pathway of Ribonucleotide Reductase by 17O Electron-Nuclear Double Resonance Spectroscopy.
J Am Chem Soc
; 143(19): 7237-7241, 2021 05 19.
Article
em En
| MEDLINE
| ID: mdl-33957040
ABSTRACT
The role of water in biological proton-coupled electron transfer (PCET) is emerging as a key for understanding mechanistic details at atomic resolution. Here we demonstrate 17O high-frequency electron-nuclear double resonance (ENDOR) in conjunction with H217O-labeled protein buffer to establish the presence of ordered water molecules at three radical intermediates in an active enzyme complex, the α2ß2 E. coli ribonucleotide reductase. Our data give unambiguous evidence that all three, individually trapped, intermediates are hyperfine coupled to one water molecule with Tyr-O···17O distances in the range 2.8-3.1 Å. The availability of this structural information will allow for quantitative models of PCET in this prototype enzyme. The results also provide a spectroscopic signature for water H-bonded to a tyrosyl radical.
Texto completo:
1
Coleções:
01-internacional
Contexto em Saúde:
3_ND
Base de dados:
MEDLINE
Assunto principal:
Ribonucleotídeo Redutases
/
Tirosina
/
Água
Tipo de estudo:
Diagnostic_studies
Idioma:
En
Revista:
J Am Chem Soc
Ano de publicação:
2021
Tipo de documento:
Article