Covalent Binding and Interstrand Cross-Linking of Duplex DNA by Dirhodium(II,II) Carboxylate Compounds

Abstract

The study of the interactions of double-stranded (ds) DNA with the dirhodium carboxylate compounds Rh(2)(O(2)CCH(3))(4)(H(2)O)(2) (Rh1), [Rh(2)(O(2)CCH(3))(2)(CH(3)CN)(6)](BF(4))(2) (Rh2), and Rh(2)(O(2)CCF(3))(4) (Rh3) supports the presence of covalently linked DNA adducts, including stable DNA interstrand cross-links. The present biochemical study refutes earlier claims that no reaction between dirhodium compounds and dsDNA occurs. The reversal behavior of these interstrand cross-links in 5 M urea at 95 degrees C (for different heating times) implies the presence of various coordination modes involving ax/ax, ax/eq, and eq/eq DNA interactions with the dirhodium core. The reaction rates of the dirhodium compounds with dsDNA were determined spectroscopically and are in the order Rh1 << Rh2 < Rh3. This difference in behavior of the three dirhodium compounds correlates with the lability of the leaving groups and corresponds to the extent of interstrand cross-link formation by these compounds on a 123 bp DNA fragment, as observed by denaturing polyacrylamide gel electrophoresis (dPAGE). Since all three dirhodium compounds form covalent Rh-DNA adducts, including interstrand cross-links, it is important that DNA be considered a potential target for biological activity of these dirhodium carboxylate compounds.

Antitumor pentamethylcyclopentadienyl rhodium complexes of maltol and allomaltol: Synthesis, solution speciation and bioactivity

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A Planar Schiff Base Platinum(II) Complex: Crystal Structure, Cytotoxicity and Interaction with DNA

“…Then the gel was visualized and photographed using a BIO-RAD imaging system under a UV-Vis transilluminator. [23][24][25] Statistics The data processing included the Student's ttest with p≤0.05 taken as significance level, using SPSS 13.0. C-NMR, and ESI-MS spectroscopy as well as single crystal X-ray diffraction.…”

Fingerprinting the junctions of RNA structure by an open-paddlewheel diruthenium compound

“…Dirhodium compounds with paddlewheel structure have the capacity to form covalent links with DNA (Dunham et al 2005) and tRNA (Rubin and Sundaralingam 1984). Although their diruthenium counterparts (Fig.…”