INGEBI   02650
INSTITUTO DE INVESTIGACIONES EN INGENIERIA GENETICA Y BIOLOGIA MOLECULAR "DR. HECTOR N TORRES"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Cytochrome P450 reductases in Trypanosoma cruzi. A posible drug resístance mechanism.
Autor/es:
PORTAL PATRICIO; FERNÁNDEZ VILLAMIL SILVIA; ALONSO GUILLERMO D; FLAWIÁ MIRTHA M; TORRES HÉCTOR N; PAVETO CRISTINA
Lugar:
Rosario, Santa Fe, Argentina
Reunión:
Congreso; XLII Reunión Anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular.; 2006
Institución organizadora:
Sociedad Argentina de Investigaciones Bioquímicas y Biología Molecular (SAIB)
Resumen:
Cytochrome P450s (CYP) system is involved in the synthesis of endogenous compounds such as steroids, fatty acids and prostaglandins as well as activation and detoxification of foreign compounds including therapeutic drugs. Cytochrome P450 reductase (CPR) is the electron donor necessarily associated to CYP to achieve optimal activity. A NADPH dependent cytochrome c reductase activity has been previously demonstrated in T.cruzi by biochemical approaches. We present here the cloning and characterization of three sequences codifying for respective proteins homologous to CPRs, all of them showing the FMN, FAD and NADPH domains characteristic of reductases superfamily. Two of them, CPR (A) and CPR (B) were subcloned and expressed in bacterial system. The kinetic behavior of both enzymes is similar to those of mammalians, and they were active in vitro using reconstituted heterologous systems. The expression of both enzymes was demonstrated in soluble subcellular fractions of epimastigotes from CL Brener Strain, and confirmed by immunofluorescence (IFI) microscopy. The overexpression of CPR (B) was achieved in epimastigote cells and confirmed by Southern and Western blot, enzyme specific activity and IFI. These overexpressing parasites showed increased survival capability to the anti-trypanosomal drugs Nifurtimox and Benznidazole