Chemical Information and Computational Modeling of Targeting Hybrid Nucleic Acid Structures of PIM1 Sequences by Synthetic Pyrrole-Imidazole Carboxamide Drugs.

DNA can adopt various distinct structural motifs, such as quadruplex, duplex, i-motifs, etc. which have multifarious applications in biomedical therapeutics. Quadruplex-duplex hybrids (QDHs) consist of the juxtaposed quadruplex and duplex motifs and are thermally stable and biologically relevant. Selective binding toward these secondary structures plays an important role in the evaluation of the structure-specific ligands. Herein, several small molecules containing anthraquinone conjugated oligopyrrole, oligoimidazole, and pyrrole-imidazole derivatives have been screened for the binding of the quadruplex-duplex nucleic acid hybrids formed in PIM1 sequences through docking and molecular dynamics (MD) simulation studies. The binding interaction of the anthraquinone polypyrrole ligands has also been checked by performing different biophysical experiments. PIM1 , being a coactivator of the MYC oncogene, can be targeted by these small molecules to control MYC expression which is overexpressed in the majority of human cancer cells. Accordingly, these cancer cell-specific and blood-compatible anthraquinone conjugated oligopyrrole ligands can be employed for anticancer therapeutic applications. Thus, the structure-activity relationship (SAR) of the screened ligands manifested prudent structural information for designing PIM1 QDHs targeting small molecules.