Charge Transfer at the Qo-Site of the Cytochrome bc1 Complex Leads to Superoxide Production.
J Phys Chem B
; 121(8): 1771-1782, 2017 03 02.
Article
em En
| MEDLINE
| ID: mdl-27983847
ABSTRACT
The cytochrome bc1 complex is the third protein complex in the electron transport chain of mitochondria or photosynthetic bacteria, and it serves to create an electrochemical gradient across a cellular membrane, which is used to drive ATP synthesis. The purpose of this study is to investigate interactions involving an occasionally trapped oxygen molecule (O2) at the so-called Qo site of the bc1 complex, which is one of the central active sites of the protein complex, where redox reactions are expected to occur. The investigation focuses on revealing the possibility of the oxygen molecule to influence the normal operation of the bc1 complex and acquire an extra electron, thus becoming superoxide, a biologically toxic free radical. The process is modeled by applying quantum chemical calculations to previously performed classical molecular dynamics simulations. Investigations reveal several spontaneous charge transfer modes from amino acid residues and cofactors at the Qo-site to the trapped O2 molecule.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oxigênio
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Rhodobacter capsulatus
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Superóxidos
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Complexo III da Cadeia de Transporte de Elétrons
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article