Characterization of the Binding Interaction of [Ni(GFS)(Phen)(H۲O)]Cl Complex with HSA under Physiological Conditions Using Multi-Spectroscopic and Molecular Docking Techniques

The binding interaction of the [Ni(GFS)(Phen)(H۲O)]Cl complex with human serum albumin (HSA) under physiological conditions was systematically investigated using multi-spectroscopic techniques and molecular docking analysis. UV-Vis absorption and fluorescence quenching studies demonstrated that the complex interacts with HSA mainly through a static quenching mechanism. Thermodynamic parameters (∆G°, ∆H°, ∆S) revealed that the binding process is spontaneous and governed by hydrogen bonding and van der Waals interactions. Site marker displacement experiments indicated that the complex can bind to both Sudlow's site I (subdomain IIA) and site II (subdomain IIIA). Circular dichroism (CD) spectra confirmed minor conformational changes in HSA secondary structure with a slight decrease in α-helix content. Molecular docking simulations supported these experimental findings and illustrated favorable binding orientations within the protein binding pockets. These results provide useful insights into the pharmacokinetic behavior and potential drug-delivery applications of Ni(II) complexes.

Keywords:

Ni(II) complex , Human serum albumin (HSA) , Fluorescence quenching , Molecular docking , Circular dichroism spectroscopy