Dynamics and Thermodynamics of Dimerization of Parallel G-Quadruplexed DNA Formed from d(TTAG<i>_n</i>) (<i>n</i> = 3−5)

Abstract

Parallel G-quadruplexes formed from oligonucleotide sequences, d(TTAGn), where n = 3-5, have been shown to form a dimer through end-to-end stacking of 3'-terminal G-tetrads. The monomers and dimers of the G-quadruplexes are in dynamic equilibrium with an exchange rate of approximately 1 s-1. A thermodynamic study demonstrated that the dimerization of the G-quadruplexes is largely enthalpic in origin.