Non-covalent interaction of 2,6-dialkyl-substituted BODIPY with human serum albumin

The possibility of using highly hydrophobic BODIPY dyes as promising fluorescent markers for hydrophobic regions of proteins has been proven. Using spectral methods and molecular docking for 1,3,5,7-tetramethyl-substituted BODIPY and its seven derivatives bearing alkyl groups of various lengths at the 2,6-positions, the effect of their hydrophobicity on the affinity for human serum albumin (HSA) was determined. It was found that all the investigated dyes form stable supramolecular complexes with HSA, while the nature of the fluorescence response of BODIPY changes from quenching to enhancement due to an increase in the length of the alkyl substituents.