Modeling of BSA–metal ion-acrylic acid complex by theoretical methods: Semi-empirical PM6 and docking study

Albumin is the most prominent plasma protein, and one of its main functions is the transport of a large number of chemical compounds. In order to understand the nature of the transport and distribution of these compounds within biological organisms, it is important to examine the interactions of ions and molecules with proteins. In this work, the binding constants of experimentally studied metal–BSA complexes were calculated by using computational chemistry and molecular docking methods. Bovine serum albumin (BSA), polyacrylic acid (PAA) and eight different metal ions (Cd ²⁺ , Co ²⁺ , Cu ⁺ , Cu ²⁺ , Fe ²⁺ , Mn ²⁺ , Ni ²⁺ and Zn ²⁺ ) were investigated by molecular docking study. The study was carried out in two stages. As the first step, the stability of the complexes was calculated by PM6 method. In the second step, the complex formation energies of the stable ligands were performed using AutoDock 4.2. BSA–Cu ²⁺ –PAA complex was found to be the most stable complex in all the metal complexes that have been studied so far whereas BSA–PAA complex structure was not subjected to experimental study with Cu ⁺ ion previously. In this study, BSA–Cu ⁺ –PAA complex was found to be the most stable (binding energy: –8.15 kcal/mol) which gave the best binding energy in the obtained results.