Binding Mechanism of Nitro Musks to Human Lactoferrin: Multispectral Approach, Docking and Molecular Dynamics Simulation

Nitro musks are highly bioaccumulative and potentially carcinogenic, commonly used as additives in fabric softeners, detergents, and other household products. Furthermore, these substances have been detected in breast milk and human adipose tissue, posing a risk of direct exposure to pregnant women and infants. Human lactoferrin (HLF) is abundant in colostrum, and plays an important role in the non-specific immune system of the human body. In this study, the mechanisms of action of two nitro musk compounds, typical examples of synthetic musks, with HLF were investigated using molecular docking, dynamics simulation and multispectral methods. The fluorescence findings demonstrated that nitro musks quenched the intrinsic fluorescence of human lactoferrin through static quenching. Thermodynamic analysis of the binding parameters suggested that hydrophobic interactions acted synergistically in the formation of the complex. Moreover, analyses utilizing multispectral techniques, such as Fourier transform infrared (FTIR) spectroscopy, validated that the microenvironment and structure of HLF were altered in the presence of nitro musks. Finally, molecular docking and molecular dynamics simulations were employed to explore the specific binding mode of nitro musks with HLF and to assess the stability of the complex. These findings may provide a reference for assessing health risks to pregnant women and infants.