AT-dependent luminescence of DNA-threading ruthenium complexes
Journal article, 2007

Whereas the emission from the ruthenium complex Delta Delta-[mu-bidppz(phen)(4)RU2](4+) (P) is five times larger when intercalated into poly(dAdT)(2) than when intercalated into ct-DNA, the homologue Delta Delta-[mu-bidppz(bipy)(4)RU2](4+) (B) has a smaller quantum yield and a red-shifted emission. The origin of this difference is here investigated by studying intercalation into oligonucleotides containing a central AT-tract. Increasing the length of the AT-tract increases the emission quantum yield for P but decreases it for B. However, not even four helix turns of AT base pairs is enough to mimic poly(dAdT)(2). B and P thus use the increased flexibility with increasing length of the AT-tract in opposite ways, whereas B gets more prone to quenching by water, P gets more protected from quenching. The earlier reported gradual increase of the intercalation rate with AT-stretch length is thus paralleled by a gradual change in the equilibrium properties of the intercalated state. (c) 2007 Elsevier B.V. All rights reserved.


Fredrik Westerlund

Chalmers, Chemical and Biological Engineering, Physical Chemistry

Per Lincoln

Chalmers, Chemical and Biological Engineering, Physical Chemistry

Biophysical Chemistry

0301-4622 (ISSN)

Vol. 129 1 11-17

Subject Categories

Chemical Sciences



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