Interaction between N-phenyl-1-naphthylamine and β-lactoglobulin / N-fenil-1-naftilamin and β-laktoglobulin arasındaki etkileşim

Abstract Objective: We aimed to explore the interaction between hydrophobic molecule N-phenyl-1-naphthylamine (AN) and major bovine milk protein β-lactoglobulin (β-LG) in aqueous solution. Methods: We use a combination of experiment and theoretical calculation to study how the β-lactoglobulin and AN interact. Fluorescence spectra were recorded on an F-4500 fluorescence spectrometer. The absorption spectra of AN were recorded on a 2250 UV-vis spectrophotometer. The crystal structure of β-LG (1B0O) is obtained from Protein Data Bank. Molecular docking was carried out using the AutoDock4.2 software package. The PyMOL molecular viewer and the MGLTools are used to render the output and to calculate the distance between nearest atoms. Results: A 1: 1 complex were found to be formed and the N-phenyl-1-naphthylamine binding site and Trp-19 residues of β-lactoglobulin was calculated to be 2.28 nm. The interaction force between the molecule and β-lactoglobulin was suggested to be mainly hydrophobic force through the calculated thermodynamic parameters of the reaction. Autodock research also further proved the interaction mode. The binding affects no conformation of the β-lactoglobulin. Moreover, it stabilizes the fold of the protein. The binding constants of oleate to β-lactoglobulin is also calculated by competitive binding experiments. Conclusion: β-lactoglobulin, by virtue of their ability to enhance solubility and stability of AN, can provide more information about its function as a versatile carrier for small bioactive molecules. AN could also be utilized as a reference to detect the binding of other small ligands to the protein by calculating the binding constants of oleate to β-lactoglobulin as a example.