cb5009926_si_001.pdf (717.64 kB)
Positional Impact of Fluorescently Modified G‑Tetrads within Polymorphic Human Telomeric G‑Quadruplex Structures
journal contribution
posted on 2015-05-15, 00:00 authored by Michael Sproviero, Kaila
L. Fadock, Aaron A. Witham, Richard A. MandervilleEmissive C8-aryl-2′-deoxyguanosines
placed within G-tetrads
of G-quadruplex structures are useful probes for distinguishing G-quadruplexes
from duplex structures using fluorescence spectroscopy. Here, we report
the positional impact of C8-furyl-dG (FurdG) on G-quadruplex
folding in the human telomere 22-mer oligonucleotide (HTelo22, (d[AG3(T2AG3)3])). The FurdG probe was inserted into four different positions within the three
unique G-tetrads of HTelo22, and G-quadruplex folding was monitored
by UV–vis thermal denaturation, circular dichroism, and fluorescence
spectroscopy. Our studies demonstrate the impacts of C8-aryl-dG adduct
formation on G-quadruplex polymorphism in K+ solution and
in the presence of the additives and cosolutes, CH3CN,
polyethylene glycol (PEG-600), and N-methyl mesoporphyrin
IX (NMM). Our experiments predict that C8-aryl-dG derivatives can
serve as useful tools for various in vitro studies
aimed at understanding both the implications of DNA adduct formation
within G-quadruplex structures and the unique implications imposed
by various folding topologies on biological function/recognition.