| Popis: |
Here we describe studies of metallointercalators bound to DNA. These octahedral transition metal complexes primarily bind noncovalently by stacking within the DNA helix. Given the rich photophysics and photochemistry of the ruthenium and rhodium complexes we employ, we have used a variety of biophysical studies to characterize their interactions with DNA. X-ray crystallography has also provided atomic resolution detail as to their binding to the duplex. Complexes have been designed that target DNA with high specificity. We have, for example, designed metal complexes that bind specifically to mismatched sites in the DNA duplex, and these have found application in the detection of single nucleotide polymorphisms and studies of mismatch repair deficiency. The photophysical properties of the metal complexes along with their intercalative stacking have been useful in particular as tools to characterize long-range charge transport in DNA. Using metallointercalators tethered to the duplex, oxidative damage to DNA from a distance has been demonstrated. The metallointercalators may serve as models for DNA-binding proteins, not only in binding DNA sites with high specificity, but also in carrying out electron transfer chemistry mediated by the DNA base-pair stack. Certainly these metallointercalators have proven to be powerful probes of this chemistry. |
