JBIC Journal of Biological Inorganic Chemistry

, Volume 15, Issue 5, pp 629–639

Metal–bipyridine complexes in DNA backbones and effects on thermal stability

  • Mildred M. Rodriguez-Ramos
  • Jonathan J. Wilker
Original Paper

DOI: 10.1007/s00775-010-0630-5

Cite this article as:
Rodriguez-Ramos, M.M. & Wilker, J.J. J Biol Inorg Chem (2010) 15: 629. doi:10.1007/s00775-010-0630-5


Modified oligonucleotides are showing potential for multiple applications, including drug design, nanoscale building blocks, and biosensors. In an effort to expand the functionality available to DNA, we have placed chelating ligands directly into the backbone of DNA. Between one and three nucleosides were replaced with 2,2′-bipyridine phosphates in 23-mer duplexes of DNA. An array of metal ions were added (Fe2+, Co2+, Ni2+, Cu2+, Zn2+, and Pt2+) and the influences on duplex stability were examined by melting temperature studies. Titrations and UV–vis absorption spectroscopy were used to provide insights into the nature of the metal complexes formed. We found that Ni2+ binding to 2,2′-bipyridine typically provided the greatest increase in duplex stability relative to the other metal ions examined. For example, addition of Ni2+ to one 2,2′-bipyridine–DNA duplex increased the melting temperature by 13 °C, from 65.0 ± 0.3 to 78.4 ± 0.9 °C. These studies show that metal ions and backbone ligands can be used to regulate DNA structure and stability.


Bipyridine DNA Melting curves Metals Modified nucleic acids 

Supplementary material

775_2010_630_MOESM1_ESM.pdf (994 kb)
Supplementary material 1 (PDF 994 kb)

Copyright information

© SBIC 2010

Authors and Affiliations

  • Mildred M. Rodriguez-Ramos
    • 1
  • Jonathan J. Wilker
    • 1
  1. 1.Department of ChemistryPurdue UniversityWest LafayetteUSA