Decoding the intermolecular recognition mode of a potent anticancer drug, abiraterone with human serum albumin: Assessments through spectroscopic and computational techniques

Abiraterone (ABR) is an FDA-approved anticancer drug that possesses repressing properties against the progression of advanced prostate cancer. The combination of bioactive molecules with proteins in blood circulation is the primary determinant of their potential therapeutic effectiveness. Therefore, the interaction characteristics of ABR with the leading carrier protein, human serum albumin (HSA) was evaluated using multi-spectroscopic and computational techniques. The obtained results showed enhancement of HSA fluorescence upon ABR addition through a static process, and affirmed the complexation between ABR and HSA. Whereas a moderate binding strength in ABR-HSA complexation was manifested, the complex was predicted to be stabilized through hydrophobic interactions, van der Waals forces and hydrogen bonding. Inclusion of ABR to HSA appreciably guarded temperature-induced destabilization of the protein, however, it altered the encompassing medium near Trp and Tyr residues of HSA. ABR was detected to favor binding at subdomain IIIA (Sudlow's site II) of HSA and the constancy of the ABR-HSA complex was revealed.