Abstract
Transport proteins, such as serum albumins (SAs) or alpha-1-acid glycoproteins (AAGs) are carriers of endogenous and exogenous agents in the bloodstream and play a crucial role in relevant processes of living organisms. Therefore, binding of ligands to transport proteins is an important issue, which has been addressed by different methodologies. In our group, the triplet excited states of different drugs, generated by laser flash photolysis (LFP), have been used as reporters for the microenvironments experienced within the protein binding sites. Analysis of triplet decay provides valuable information on the distribution of the drug between the binding sites and its presence as the noncomplexed form in the bulk solution. This principle has been used to determine the degree of drug binding and can be extended to investigate the distribution of a drug between several compartments in host biomolecules, to assess the competition between SAs and AAGs for drug transport, or to study drug-drug interactions within protein cavities.
