Affiliations: National Institute of Research & Development for Isotopic and Molecular Technologies, PO 5, Box 700, R-400293 Cluj-Napoca, Romania | AG Biopolymerspektroskopie, Max-Delbrück-Centrum für Molekulare Medizin Berlin-Buch, Robert-Rössle-Str. 10, D-13092 Berlin, Germany
Note: [] Corresponding author: Dr. Cristina Muntean, National Institute of Research & Development for Isotopic and Molecular Technologies, PO 5, Box 700, R-400293 Cluj-Napoca, Romania. E-mail: [email protected].
Note: [] This work was carried out at the Max-Delbrück-Centrum für Molekulare Medizin Berlin-Buch, Robert-Rössle-Str. 10, D-13092 Berlin, Germany.
Abstract: Interaction of natural calf thymus DNA with Mn2+ ions was studied by means of Raman spectroscopy. Spectra of DNA in 10 mM Na-cacodylate buffer, pH 6.2, 10 mM NaCl and in buffer containing Mn2+ ions were measured at room temperature. Mn2+ concentrations varied between 0 and 0.6 M. DNA backbone conformational changes and DNA denaturation were not observed in the concentration range 0 and 0.5 M, however, DNA condensation was observed at a critical concentration of 100 mM Mn2+ that prevented the measurement of Raman spectra. Binding of Mn2+ to the charged phosphate groups of DNA is indicated in the spectra. A high affinity of Mn2+ for guanine N7 was obvious, and binding to adenine was barely suggested.
