Unravelling the molecular interactions of phenyl isothiocyanate and benzoyl isothiocyanate with human lysozyme: Biophysical and computational analyses.

[Display omitted] • Static fluorescence quenching with redshift was observed for Lyz-PT and Lyz-BT systems. • Conformation and microenvironmental changes were confirmed by 3D fluorescence and CD analysis. • Metal ions and β-cd exerted a profound effect on the binding strength of Lyz-PT and Lyz-BT systems. • Binding energy values were −4.23 kcal M - 1 (Lyz-PT system) and −4.71 kcal M - 1 (Lyz-BT system). • Docking and ASAs analysis showed interaction of several amino acid residues of Lyz with PT and BT. Phenyl isothiocyanate and benzoyl isothiocyanate are the phytochemicals present in the Brassicaceae family. They have antibacterial, antiapoptotic and antifungal properties. Protein-small molecule interaction studies are done to assess the changes in structure, dynamics, and functions of protein and to decipher the binding mechanism. This study is based on the comparative binding of PT and BT with human lysozyme using in vitro and computational techniques. UV, fluorescence emission, and FRET spectra gave insight into the complex formation, quenching mechanism, and binding parameters. Both PT and BT quenched the intrinsic fluorescence of Lyz by a static quenching mechanism. Synchronous, 3D fluorescence and CD spectroscopy substantiated conformational and microenvironmental alterations in the Lyz. The metal ions and β-cyclodextrin had a pronounced effect on the binding strength of Lyz-PT and Lyz-BT complexes. Accessible surface area analysis was determined to characterise the amino acid residue packing. Molecular docking further validated the wet lab experimental results. [ABSTRACT FROM AUTHOR]