INVESTIGADORES
CABRERIZO franco Martin
congresos y reuniones científicas
Título:
Association studies between a complex of Re(I) and biopolymers
Autor/es:
FABRICIO RAGONE; HECTOR H. MARTINEZ SAAVEDRA; FACUNDO GARCIA; JUAN G. YAÑUK; GERARDO ARGÜELLO; FRANCO M. CABRERIZO; EZEQUIEL WOLCAN ; GUSTAVO T. RUIZ
Reunión:
Congreso; 16th International Congress of Photobiology; 2014
Resumen:
The spectroscopy, photochemistry and photophysics of Re(I) carbonyl?diimine complexes fac-ReX(CO)3(a-diimine) continue to attract much research interest ever since their intriguing excited state properties were first recognized in the mid-1970s [1].   There are potential biochemical and technical applications based on the formation of adducts between transition metal complexes of Re(I), and biological macromolecules such as DNA as many of those complexes have the capacity to cause DNA damage by photoinduced oxidative strand breakage [2]. The use of transport proteins to achieve a specific accumulation of drugs in tumor cells seems to be an area of keen interest [3]. Therefore, many researchers endeavors sought to identify and characterize the association of rhenium complexes to transport proteins BSA and HSA (Bovine and Human Serum Albumin), to determine the potential application of these complexes in the delivery of drugs [4].   In previous work, we have synthesized and characterized a new water soluble complex, Re(CO)3(pterin)(H2O) (pterin = 2-amine-4-pteridinone).5 In this work we study the interaction between ReI(CO)3(pterin)(H2O) and calf thymus DNA, bacterial plasmids and synthetic polynucleotides (poly-[dCdG]2 and poly-[dAdT]2) as well as transport proteins (BSA and HSA). The type of interaction between the Re(I) complex and polynucleotides was ascertained through the effect exerted by increasing the polynucleotide concentration over the luminescence properties (quantum yields and lifetime) of ReI(CO)3(pterin)(H2O) solutions. Moreover, the effect on the conformation and the level of supercoiling that occurs by the interaction of ReI(CO)3(pterin)(H2O) with the plasmid DNA was studied by electrophoresis gel and atomic force microscopy (AFM).   Thermodynamic parameters (DH, DG and DS) and the association constant (Kb) which characterize the interaction of the complex with transport proteins such as HSA and BSA were determined by measuring the quenching of the protein fluorescence in the presence of different complex concentrations. Additionally, circular dichroism experiments helped to identify the binding site for the complex and conformational changes experienced by the protein due to the interaction.   [1]- Kumar et al Top Organomet. Chem., 29, 1, 2010 [2]- Smith et al. Coord. Chem. Rev., 255, 2666, 2011 [3]- Toneatto et al. J Inorg. Biochem., 105 (2011) 1299?1305 [4]- Bhuvaneswari et al. Inorg. Chem. Acta 375 (2011) 205?212 [5]- Ragone et al. Eur J Inorg. Chem., 4801, 2012