Conformational Dynamics of DNA G-Quadruplex in Solution Studied by Kinetic Capillary Electrophoresis Coupled On-line with Mass Spectrometry**

Abstract

G-quadruplex-forming DNA/RNA sequences play an important role in the regulation of biological functions and development of new anticancer and anti-aging drugs. In this work, we couple on-line kinetic capillary electrophoresis with mass spectrometry (KCE-MS) to study conformational dynamics of DNA G-quadruplexes in solution. We show that peaks shift and its widening in KCE can be used for measuring rate and equilibrium constants for DNA-metal affinity interactions and G-quadruplex formation; and ion mobility mass spectrometry (IM-MS) provides information about relative sizes, absolute molecular masses and stoichiometry of DNA complexes. KCE-MS separates a thrombin-binding aptamer d[GGTTGGTGTGGTTGG] from mutated sequences based on affinity to potassium, and reveals the apparent equilibrium folding constant (K F≈150 μm), folding rate constant (k on≈1.70×10(3) s(-1) m(-1)), unfolding rate constant (k off≈0.25 s(-1)), half-life time of the G-quadruplex (t 1/2≈2.8 s), and relaxation time (τ≈3.9 ms at physiological 150 mm [K(+)]). In addition, KCE-MS screens for a GQ-stabilizing/-destabilizing effect of DNA binding dyes and an anticancer drug, cisplatin.

DOI: 10.1002/open.201400002

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@inproceedings{Mironov2014ConformationalDO, title={Conformational Dynamics of DNA G-Quadruplex in Solution Studied by Kinetic Capillary Electrophoresis Coupled On-line with Mass Spectrometry**}, author={Gleb G. Mironov and Victor Okhonin and Nasrin Khan and Christopher M. Clouthier and Maxim V Berezovski}, booktitle={ChemistryOpen}, year={2014} }