Photophysical characterization of perylene derivatives and their interaction with human serum albumin

The study of the binding and effects of polyaromatic hydro-carbons (PAH) to proteins remains one of the fundamental aspects of research in biophysics. Among other processes, ligand binding can regulate the function of proteins including inhibiting their action. Binding to small ligands remains a very important aspect in the study of the function of many proteins. We have investigated a number of novel perylene analogues. The investigation includes the photophysical characterization of perylene diimides and their interaction with HSA. In this study we have shown that 3,9-disubstitutes perylenes show weak affinity to binding with HSA and their irradiation produces no observable structural effects on the bound protein. Perylene Diimides were photophysically characterized in organic solvents. PDI phenylalanine and leucine are the only PDIs spectroscopically observable in aqueous solution and bind with HSA with great affinity. Resonance energy transfer was observed in PDIF bound to HSA with an energy efficiency of 0.268.