Structural Interpretation of Metastable States in Myoglobin-NO.
Angew Chem Int Ed Engl
; 55(34): 10126-30, 2016 08 16.
Article
en En
| MEDLINE
| ID: mdl-27410027
Nitric oxide binding and unbinding from myoglobin (Mb) is central to the function of the protein. By using reactive molecular dynamics (MD) simulations, the dynamics following NO dissociation were characterized in both time and space. Ligand rebinding can be described by two processes on the 10â
ps and 100â
ps timescale, which agrees with recent optical and X-ray absorption experiments. Explicitly including the iron out-of-plane (Fe-oop) coordinate is essential for a meaningful interpretation of the data. The proposed existence of an "Fe-oop/NO-bound" state is confirmed and assigned to NO at a distance of approximately 3â
Å away from the iron atom. However, calculated XANES spectra suggest that it is diffcult to distinguish between NO close to the heme-Fe and positions further away in the primary site. Another elusive state, with Fe-ON coordination, was not observed experimentally because it is masked by the energetically more favorable but dissociative (4) A state in this region, which makes the Fe-ON local minimum unobservable in wild-type Mb. However, suitable active-site mutations may stabilize this state.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Mioglobina
/
Óxido Nítrico
Idioma:
En
Revista:
Angew Chem Int Ed Engl
Año:
2016
Tipo del documento:
Article
País de afiliación:
Suiza
Pais de publicación:
Alemania