Elucidating the binding mechanism between bovine serum albumin and TiO2 nanoparticles with diverse properties: Insights from spectroscopic methods and molecular docking simulation

Abstract

The interaction mechanism between bovine serum albumin (BSA) and titanium dioxide (TiO2) nanoparticles with different shapes, surface charge and hydrophobic properties was studied using multiple spectral methods and molecular docking simulation. UV–vis spectra showed that when BSA interacted with the four TiO2 NPs, the TiO2 nanoparticles and BSA formed a stable ground state complex. Fluorescence spectra showed that the binding capacities of four different types of TiO2 nanoparticles with BSA are as follows: spherical TiO2 (s-TiO2) > rod-shaped TiO2 (r-TiO2) > positively charged TiO2 (c-TiO2) > hydrophobic TiO2 (h-TiO2). The results of synchronous fluorescence, circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopy revealed that s-TiO2, r-TiO2, and c-TiO2 have a weak effect on the conformation of BSA, whereas h-TiO2 has a greater effect. Molecular docking and MD simulations results show that the content of hydroxyl groups plays a key role in the binding capacity.