Autor(en): | Stratmann, Lukas M. Kutin, Yury Kasanmascheff, Müge Clever, Guido H. |
Titel: | Precise distance measurements in DNA G-quadruplex dimers and sandwich complexes by pulsed dipolar EPR spectroscopy |
Sprache (ISO): | en |
Zusammenfassung: | DNA G-quadruplexes show a pronounced tendency to form higher-order structures, such as π-stacked dimers and aggregates with aromatic binding partners. Reliable methods for determining the structure of these non-covalent adducts are scarce. Here, we use artificial square-planar Cu(pyridine)4 complexes, covalently incorporated into tetramolecular G-quadruplexes, as rigid spin labels for detecting dimeric structures and measuring intermolecular Cu2+–Cu2+ distances via pulsed dipolar EPR spectroscopy. A series of G-quadruplex dimers of different spatial dimensions, formed in tail-to-tail or head-to-head stacking mode, were unambiguously distinguished. Measured distances are in full agreement with results of molecular dynamics simulations. Furthermore, intercalation of two well-known G-quadruplex binders, PIPER and telomestatin, into G-quadruplex dimers resulting in sandwich complexes was investigated, and previously unknown binding modes were discovered. Additionally, we present evidence that free G-tetrads also intercalate into dimers. Our transition metal labeling approach, combined with pulsed EPR spectroscopy, opens new possibilities for examining structures of non-covalent DNA aggregates. |
Schlagwörter: | DNA G-quadruplexes Metal base-pairing p-stacking EPR spectroscopy |
URI: | http://hdl.handle.net/2003/40311 http://dx.doi.org/10.17877/DE290R-22186 |
Erscheinungsdatum: | 2020-10-16 |
Rechte (Link): | https://creativecommons.org/licenses/by/4.0/ |
Enthalten in den Sammlungen: | Lehrstühle für Anorganische Chemie |
Dateien zu dieser Ressource:
Datei | Beschreibung | Größe | Format | |
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anie.202008618.pdf | 6.57 MB | Adobe PDF | Öffnen/Anzeigen |
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