Exploring the interaction mechanism between fibrinogen and copper oxide nanoparticles via multi-spectroscopy and...

Fibrinogen is a key component of the coagulation cascade, and its structural alterations upon interaction with other substances can impact the function. Copper oxide nanoparticles (CuO NPs) are a widely used nanomaterial that can enter the blood and interact with fibrinogen. In this study, the molecular mechanism for the formation of fibrinogen-CuO NPs complexes was investigated using spectroscopic techniques, molecular docking and dynamics simulations. The results demonstrated that fibrinogen spontaneously bound to CuO NPs via hydrogen bonding and van der Waals forces, resulting in the fluorescence quenching of fibrinogen, with the quenching mechanism being static quenching. This interaction induced structural changes in fibrinogen, including increased hydrophobicity around tyrosine (Tyr) residues and reduced α-helical content. Molecular docking and dynamics simulations further showed the formation of stable fibrinogen-CuO NPs complexes, leading to structural loosening of fibrinogen. These structural perturbations might lead to misfolding or aggregation, thereby impairing the coagulation function of fibrinogen. Investigation of the interaction between fibrinogen and CuO NPs will help to understand the behavior and effects of nanoparticles upon entry into complex biological systems as well as the molecular mechanisms of protein corona formation, contributing to the development and application of fibrinogen and CuO NPs.