Supplementary Figure 4: Biophysical characterization of the interaction of small-molecule G4 ligands with the DNA and RNA L1Hs quadruplexes.
From: G-quadruplex structures within the 3′ UTR of LINE-1 elements stimulate retrotransposition
Thermal denaturation profiles of L1HS-DNA-G4 (a) and L1HS-RNA-G4 (b) in the presence or absence of the small molecules PDS, PhenDC3, 12459, PDC12 and PDC20 followed by CD spectroscopy at 263 nm. The nucleic acids were annealed at 1.5 μM in a 5 mM and 1mM KCl containing buffer for the DNA or RNA quadruplex respectively. (c) Extracted melting temperatures (T1/2) from the CD melting experiments (data represent mean values ± s.d.; n = 3 technical replicates, i.e. independent melting experiments). (d) Concentration-dependent stabilization effect of the small molecules on Fl-L1HS-DNA-G4 (a dual fluorescently labeled L1HS DNA quadruplex) followed by FRET melting experiments (data represent mean values ± s.d.; n = 3 technical replicates). (e-f) Thermal denaturation profiles and extracted melting temperatures (T1/2) of Fl-L1Hs-DNA-G4 in the presence of PDC12 and an increasing concentration of a double-stranded DNA competitor (dsDNA). Fl-L1Hs-DNA-G4 was annealed at 100 nM in a 5 mM KCl containing buffer. All molecules, except PDC20, were found to stabilize both the DNA and RNA L1Hs quadruplexes. The newly reported compound PDC12 was found to be selective for the L1Hs-DNA quadruplex over double-stranded DNA (data in f represent mean values ± s.d.; n = 3 technical replicates).
