| Autor: |
Soundarapandian, Suganthi, Alexander, Aleyamma, Sumohan Pillai, Archana, Manikandan, Varnitha, Enoch, Israel V. M. V., Yousuf, Sameena |
| Zdroj: |
Journal of Biomolecular Structure and Dynamics; June 2023, Vol. 41 Issue: 9 p3791-3799, 9p |
| Abstrakt: |
AbstractClinical applicability of G-quadruplexes as anticancer drugs is an area of current interest. Identification of supramolecular systems for selective targeting G-quartets is particularly intriguing. In this work, the DNA binder Berberine is encapsulated inside the molecular cavity of the synthesised host structure, Fluoresecein-β-cyclodextrin conjugate. The host: guest complex is characterized and the mode of binding is optimized using two dimensional rotating-frame Overhauser effect spectroscopy. The conjugate is examined for its binding to quadruplex DNAs viz., kit22, myc22, telo24and the duplex calf-thymus DNA before and after Berberine encapsulation. UV–vis and fluorescence spectroscopic methods were employed to determine the strength of binding of the complex with the DNAs. The binding strength and the stoichiometry of the host: guest complex are 1.9 × 106 mol−1dm3and 1:1, respectively. A quenching of fluorescence of the quadruplex kit22and duplex ctDNA is observed on binding to the Fluorescein-β-cyclodextrin conjugate. The quadruplexes of myc22and telo24display an enhanced fluorescence on binding to the modified cyclodextrin. The Stern-Volmer quenching constants are 1.4 × 106 mol−1dm3and 3.8 × 105 mol−1dm3for binding to kit22and ctDNA respectively. kit22shows a different emission profile on interacting with the Berberine encapsulated conjugate, whereas all the other quadruplexes and duplex exhibit similar emission profiles. The results indicate a variation in the binding mode and strength of the ligand-quadruplexes and depend on the conformation of the quadruplexes.Communicated by Ramaswamy H. Sarma |
| Databáze: |
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