Biological Evaluation, Chelation, and Molecular Modeling Studies of Novel Metal-Chelating Inhibitors of NF-κB-DNA Binding: Structure Activity Relationships

Abstract

Previously, we have reported that aurintricarboxylic acid (ATA) is one of the most potent inhibitors of the DNA binding of transcription factor NF-kappaB. We now report the NF-kappaB-DNA binding inhibitory activity of ATA analogues. An electrophoretic mobility shift assay has shown that bromopyrogallol red (BPR) is the most effective inhibitor of NF-kappaB-DNA binding among the studied analogues. The molecular modeling studies showed that BPR makes a strong network of hydrogen bonds with the DNA-binding region of the p50 subunit of NF-kappaB and has electronegative potential on its peripheral surface. Because zinc has been reported to influence the DNA binding of NF-kappaB, the interaction of these analogues with zinc was studied. Chemical speciation and formation-constant studies showed that BPR forms the most stable 1:1 complex with zinc. BPR has also been found to be the most potent antioxidant among the studied analogues.