| Autor: |
Neitz H; Institute of Organic Chemistry, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany., Bessi I; Institute of Organic Chemistry, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany., Kuper J; Rudolf-Virchow-Zentrum - Center for Integrative and Translational Bioimaging, Universität Würzburg, Josef-Schneider-Straße 2, 97080 Würzburg, Germany., Kisker C; Rudolf-Virchow-Zentrum - Center for Integrative and Translational Bioimaging, Universität Würzburg, Josef-Schneider-Straße 2, 97080 Würzburg, Germany., Höbartner C; Institute of Organic Chemistry, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.; Center for Nanosystems Chemistry (CNC), Universität Würzburg, 97074 Würzburg, Germany. |
| Abstrakt: |
Covalent crosslinking of DNA strands provides a useful tool for medical, biochemical, and DNA nanotechnology applications. Here we present a light-induced interstrand DNA crosslinking reaction using the modified nucleoside 5-phenylethynyl-2'-deoxyuridine ( Phe dU). The crosslinking ability of Phe dU was programmed by base pairing and by metal ion interaction at the Watson-Crick base pairing site. Rotation to intrahelical positions was favored by hydrophobic stacking and enabled an unexpected photochemical alkene-alkyne [2 + 2] cycloaddition within the DNA duplex, resulting in efficient formation of a Phe dU dimer after short irradiation times of a few seconds. A Phe dU-dimer-containing DNA was shown to efficiently bind a helicase complex, but the covalent crosslink completely prevented DNA unwinding, suggesting possible applications in biochemistry or structural biology. |
