Cyanine Dye Interactions with Quadruplex and Duplex DNA: Changes in Conformation, Stability, and Affinity

There is a high demand for quadruplex-specific compounds that not only bind preferentially to quadruplex DNA over duplex DNA, but also bind to one quadruplex motif over other motifs. Quadruplex structures are recognized as common occurrences in cancer cells, and if a compound could stabilize this structure, it may serve as an effective anti-cancer treatment with minimal side effects. In this study, cyanine dyes’ interactions with DNA were analyzed with fluorescence titrations, UV-Vis thermal studies, circular dichroism titrations, and surface plasmon resonance (SPR) analysis. With these techniques, binding affinity, DNA stabilization, and conformational shifts were analyzed to determine if cyanine dyes could act as quadruplex-specific binding compounds for possible cancer treatments. INDEX WORDS: G-Quadruplex, Cyanine dyes, Thermal Melting, Circular Dichroism, Fluorescence, Surface Plasmon Resonance, Isothermal Calorimetry, Electrospray Ionization Mass Spectrometry CYANINE DYE INTERACTIONS WITH QUADRUPLEX AND DUPLEX DNA: CHANGES IN CONFORMATION, STABILITY, AND AFFINITY