Novel peptide-based copper(II) complexes for total hydrolytic cleavage of DNA

Abstract

Stable CuII complexes with histamine- and histidine-containing dipeptides histidylserine and histidylphenylalanine have been developed. Their interaction in solution has been investigated, and the stability of their complexes was determined. The nature of binding in these complexes has been explained with the help of potentiometric pH titrations and 1H-NMR spectroscopy. The geometry of these complexes has been established by electronic spectra. The DNA-binding and -cleavage abilities of these CuII complexes have been probed by the absorption, thermal denaturation, fluorescence, and electrophoresis experiments. The results suggest that these peptide-based CuII complexes effectively bind and efficiently cleave DNA under mild biological conditions. Since CuII complexes are known to play an important role in phosphodiester bond cleavages, these results assume importance. © 2005 Verlag Helvetica Chimica Acta AG, Zürich.