Anionic Ferrocenyl Peptide Surfactants: Interaction with Bovine Serum Albumin and Inhibition of Amyloids

The interaction study of anionic surfactants with albumins has emerged as an important area of research and is widely considered as a model for gaining fundamental insight into surfactant protein binding, which is helpful in both chemical and biological applications. This study involves the interactions of five ferrocene-linked peptide anionic surfactants (FcS1-5) with bovine serum albumin (BSA). Micropolarity assay, steady state fluorescence (at different temperatures) and circular dichroism spectroscopic techniques were utilized to evaluate the interaction of FcS-BSA systems. The ferrocenyl surfactant quenches the intrinsic fluorescence of BSA due to ground state complexation. The binding of FcS with BSA is predominantly through hydrophobic interactions. Circular dichroism study reveals that ferrocenyl peptides can maintain the conformation of BSA in its native state up to a specific concentration, beyond which the BSA structure is disrupted. Among all FcS, FcS4 was found to be the best, with low critical aggregation concentration and stronger binding with BSA. Further, the ability of FcS4 to inhibit amyloidosis in BSA was established using Thioflavin T assay and fluorescence microscopy. These ferrocenyl peptide amphiphiles have the potential to be used in biological and pharmaceutical industry resulting from their ability to interact with intrinsically disordered proteins.