Reactions of copper macrocycles with antioxidants and HOCl: potential for biological redox sensing.
Biometals
; 26(1): 85-96, 2013 Feb.
Article
en En
| MEDLINE
| ID: mdl-23160798
ABSTRACT
A series of simple copper N(2)S(2) macrocycles were examined for their potential as biological redox sensors, following previous characterization of their redox potentials and crystal structures. The divalent species were reduced by glutathione or ascorbate at a biologically relevant pH in aqueous buffer. A less efficient reduction was also achieved by vitamin E in DMSO. Oxidation of the corresponding univalent copper species by sodium hypochlorite resulted in only partial (~65 %) recovery of the divalent form. This was concluded to be due to competition between metal oxidation and ligand oxidation, which is believed to contribute to macrocycle demetallation. Electrospray mass spectrometry confirmed that ligand oxidation had occurred. Moreover, the macrocyclic complexes could be demetallated by incubation with EDTA and bovine serum albumin, demonstrating that they would be inappropriate for use in biological systems. The susceptibility to oxidation and demetallation was hypothesized to be due to oxidation of the secondary amines. Consequently these were modified to incorporate additional oxygen donor atoms. This modification led to greater resistance to demetallation and ligand oxidation, providing a better platform for further development of copper macrocycles as redox sensors for use in biological systems.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Ácido Hipocloroso
/
Cobre
/
Éteres Cíclicos
/
Complejos de Coordinación
/
Antioxidantes
Límite:
Animals
Idioma:
En
Revista:
Biometals
Asunto de la revista:
BIOQUIMICA
Año:
2013
Tipo del documento:
Article
País de afiliación:
Reino Unido