Effect of chain length on the interactions of sodium N-alkyl prolinates with bovine serum albumin: a spectroscopic investigation and molecular docking simulations

The interaction of anionic surfactants with serum albumin has emerged as an important area of research and is considered as a model for gaining fundamental insight into surfactant-protein binding, which is useful in both chemical and biological applications. This study involves the interactions of three synthesized proline-based anionic surfactants of varying chain lengths (C-8, C-10, and C-12) with bovine serum albumin (BSA) using different techniques, including fluorescence, H-1 NMR, and FT-IR spectroscopy. The study indicated that the binding of the proline surfactants with BSA followed a static quenching process, with an increase in binding ability upon increasing chain length. FT-IR studies revealed a change in the secondary structure of BSA upon binding with the proline surfactant, while H-1 NMR investigations indicated the proximity of the long alkyl chain of the surfactant with tryptophan residues of BSA. Molecular docking studies performed on the three proline surfactants with BSA revealed that the surfactants were able to bind in the vicinity of both tryptophan residues (Trp-213 and Trp-134) with an increase in the free energy of binding while increasing the chain length from C-8 to C-12. Therefore, this study provided a whole view about the interaction of BSA with anionic proline derived surfactants, which can be used as potential ingredients in pharmaceutical products.