Resumen:
ackground: Transferrin is an iron-binding blood plasma glycoprotein that controls the level of free iron in biological
fluids. This protein has been deeply studied in the past few years because of its potential use as a strategy of
drug targeting to tumor tissues. Chromium complex, [Cr(phen)3]3+ (phen = 1,10-phenanthroline), has been
proposed as photosensitizers for photodynamic therapy (PDT). Thus, we analyzed the binding of chromium
complex, [Cr(phen)3]3+, to transferrin for a potential delivery of this diimine complex to tumor cells for PDT.
Methods: The interaction between [Cr(phen)3]3+ and holotransferrin (holoTf) was studied by fluorescence
quenching technique, circular dichroism (CD) and ultraviolet (UV)?visible spectroscopy.
Results: [Cr(phen)3]3+ binds strongly to holoTfwith a binding constant around 105M−1, that depends on the pH.
The thermodynamic parameters indicated that hydrophobic interactions played amajor role in the binding processes.
The CD studies sh