Binding Properties Characterization of Cr(phen)33+ and Ru(phen)32+ Complexes with Human Lactoferrin

AbstractThis work presents research about [Cr(phen)3]3+ and [Ru(phen)3]2+ interaction with human Lactoferrin (HLf), a key carrier protein of ferric cations. The photochemical and photophysical properties of [Cr(phen)3]3+ and [Ru(phen)3]2+ have been widely studied in the last decades due to their potential use as photosensitizers in photodynamic therapy (PDT). The behavior between the complexes and the protein was studied employing UV-visible absorption, fluorescence emission, and circular dichroism spectroscopic techniques. It was found that both complexes bind to HLf with a large binding constant (Kb): 9.46x104 for the chromium complex and 4.16x104 for the ruthenium one at 299 K. Thermodynamic parameters were obtained from the Van ’t Hoff equation. Analyses of entropy (ΔS), enthalpy (ΔH), and free energy changes (ΔG) indicate that these complexes bind to HLf because of entropy-driven processes and electrostatic interactions. According to circular dichroism experiments no conformational changes have been observed in the s econdary and tertiary structure of the protein in the presence of any of the studied complexes. These experimental results suggest that [Cr(phen)3]3+ and [Ru(phen)3]2+ bind to HLf, indicating that this protein could act as a carrier of these complexes in further applications.

Source: Photochemistry and Photobiology - December 12, 2022 Category: Science Authors: Pablo Facundo Garcia, Santiago N. Saez Torillo, Angel Anzani, Gerardo Arg üello, Maxi A. Burgos Paci Tags: Research Article Source Type: research