title: Spectroscopic detection of DNA quadruplexes by vibrational circular dichroism.
abstract: The four-stranded G-quadruplex motif is a conformation frequently adopted by guanine-rich nucleic acids that plays an important role in biology, medicine, and nanotechnology. Although vibrational spectroscopy has been widely used to investigate nucleic acid structure, association of particular spectral features with the quadruplex structure has to date been ambiguous. In this work, experimental IR absorption and vibrational circular dichroism (VCD) spectra of the model quadruplex systems d(G)(8) and deoxyguanosine-5'-monophosphate (5'-dGMP) were analyzed using molecular dynamics (MD) and quantum-chemical modeling. The experimental spectra were unambiguously assigned to the quadruplex DNA arrangement, and several IR and VCD bands related to this structural motif were determined. Involvement of MD in the modeling was essential for realistic simulation of the spectra. The VCD signal was found to be more sensitive to dynamical structural variations than the IR signal. The combination of the spectroscopic techniques with multiscale simulations provides extended information about nucleic acid conformations and their dynamics.
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic. andrushchenko@uochb.cas.cz
authors.forename: Valery
authors.initials: V
authors.lastname: Andrushchenko
authors.forename: Dimiter
authors.initials: D
authors.lastname: Tsankov
authors.forename: Maria
authors.initials: M
authors.lastname: Krasteva
authors.forename: Helmut
authors.initials: H
authors.lastname: Wieser
authors.forename: Petr
authors.initials: P
authors.lastname: Bour
mesh_terms: D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D054856:G-Quadruplexes; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D011789:Quantum Theory; D013055:Spectrophotometry, Infrared
chemical_list: D004247:DNA