Discipline: Chemistry & Chemical Sciences
Subcategory: STEM Research
Bidisha Sengupta - Tougaloo College
Co-Author(s): Enleyona Weir
Quadruplex (G4/C4) forming sequences in telomeric DNA and promoter regions of oncogenes are associated with tumorogenesis. Stabilizing these unusual tetraplex structures in DNA can prevent tumor cell proliferation, which have been regarded as potential pathways for cancer therapy. In our previous studies we have proved plant flavonols as useful G4/C4 binders. In the present study, we have prepared an isopropanol extract from banana peel (BE) and performed a comparative study on the binding of BE and a flavonol morin with G4/C4 using steady state absorption, fluorescence, circular dichroism and size exclusion chromatography (SEC) measurements. Two complementary G4 and C4 single stranded oligonucleotide along with the duplex (made my hybridizing the G4/C4) were used. We noticed that in C18 HPLC the retention time of BE and morin are same, indicating similar size of the two. BE shows significant solvent dipolar relaxation when studied in solvents of different polarity. BE also exhibits excited state intra-molecular proton transfer (ESPT) similar to common flavonol like fisetin. We extended our studies on G4/C4 in presence of nicotine (NIC), which is a potent oxidative stress inducer. BE and morin exhibited different characteristics in presence of NIC. We observed BE as a better extrinsic probe than morin. Dynamic light scattering (DLS) studies determined the size of DNA molecules in bound and free states. Further studies using NMR and FTIR are underway.
Funder Acknowledgement(s): This work was supported by: NSF-RIA award 1800732 (PI), NSF-TIP award 1818528 (co-PI) Institutional Development Award (IDeA) from the NIGMS under grant number 20GM103476 (seed grant PI).
Faculty Advisor: None Listed,