Artículo
Redox-state sensing by hydrogen bonds in the CuA center of cytochrome c oxidase
Fecha de publicación:
07/2013
Editorial:
Elsevier Science Inc
Revista:
Journal Of Inorganic Biochemistry
ISSN:
0162-0134
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
Cytochrome c oxidases (CcO) couple electron transfer to active proton translocation through a gated mechanism that minimizes energy losses by preventing protons from flowing backwards or leaking. Such a complex mechanism requires that information about the redox and protonation states of the different centers be transmitted between different parts of the oxidase. Here we report a network of residues located around the electron entry point of CcO, the CuA site in subunit II, that experience collective pH equilibria around neutral pH. This network starts at the occluded side of the CuA site and extends to the interface between subunits I and II of the CcO, where the proton exit is located and through which electrons flow into subunit I. One of the residues in this network is directly involved in a hydrogen bond to one of the CuA ligands, whose strength is highly sensitive to the redox state of the metal center. We propose that this interaction mediates the transmission of redox changes from ET centers to other functional regions of the oxidase, and possibly also in other similar machineries, as part of their gating and regulatory mechanisms.
Palabras clave:
Copper Proteins
,
Electron Transfer
,
Hydrogen Bonds
,
Paramagnetic Nmr
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Identificadores
Colecciones
Articulos(IBR)
Articulos de INST.DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Articulos de INST.DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Citación
Vila, Alejandro Jose; Abriata, Luciano Andres; Redox-state sensing by hydrogen bonds in the CuA center of cytochrome c oxidase; Elsevier Science Inc; Journal Of Inorganic Biochemistry; 132; 7-2013; 18-20
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