Artículo
Advances on the interaction of polypyridyl Cr(III) complexes with transporting proteins and its potential relevance in photodynamic therapy
Fecha de publicación:
10/2011
Editorial:
Elsevier Science Inc
Revista:
Journal of Inorganic Biochemistry
ISSN:
0162-0134
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
The present study reports a detailed investigation into the interaction of [Cr(phen) 2(dppz)] 3+ and [Cr(phen) 3] 3+ with transferrin, the key protein for the transport of Fe 3+ in blood plasma; its cycle holds promise as an attractive system for strategies of drug targeting to tumor tissues. This can allow us to understand further the role of both complexes as sensitizers in photodynamic therapy (PDT). Chromium(III) complexes, [Cr(phen) 2(dppz)] 3+ and [Cr(phen) 3] 3+, (phen = 1,10-phenanthroline and dppz = dipyridophenazine), where dppz is a planar bidentate ligand with an extended π system, have been found to bind strongly with apotransferrin (apoTf) with an intrinsic binding constant, K b, of (1.8 ± 0.3) × 10 5 M - 1 and (1.1 ± 0.1) × 10 5 M - 1 at 299 K, for apoTf-[Cr(phen) 2(dppz)] 3+ and apoTf-[Cr(phen) 3] 3+, respectively. The interactions of apoTf with the different Cr(III) complexes were assessed employing UV-visible absorption, fluorescence and circular dichroism spectroscopy. The relative fluorescence intensity of the protein decreased when the increasing concentration of Cr(III) complex was added, suggesting that perturbation around the Trp and Tyr residues took place. The analysis of the thermodynamic parameters ΔG, ΔH, ΔS indicated that the presence of the Cr(III) complex stabilizes the protein with a strong entropic contribution. The binding distances and transfer efficiencies for apoTf-[Cr(phen) 2(dppz)] 3+ and apoTf-[Cr(phen) 3] 3+ binding reactions were calculated according to Föster theory of non-radiation energy transfer. All these experimental results suggest that [Cr(phen) 2(dppz)] 3+ and [Cr(phen) 3] 3+ bind strongly to apoTf indicating that this protein could act as a carrier of these complexes for further applications in PDT. © 2011 Elsevier Inc. All rights reserved.
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Articulos(IBYME)
Articulos de INST.DE BIOLOGIA Y MEDICINA EXPERIMENTAL (I)
Articulos de INST.DE BIOLOGIA Y MEDICINA EXPERIMENTAL (I)
Articulos(INFIQC)
Articulos de INST.DE INVESTIGACIONES EN FISICO- QUIMICA DE CORDOBA
Articulos de INST.DE INVESTIGACIONES EN FISICO- QUIMICA DE CORDOBA
Citación
Toneatto, Judith; Garcia, Pablo Facundo; Arguello, Gerardo; Advances on the interaction of polypyridyl Cr(III) complexes with transporting proteins and its potential relevance in photodynamic therapy; Elsevier Science Inc; Journal of Inorganic Biochemistry; 105; 10; 10-2011; 1299-1305
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