Scheme of the Complex Formation of DNA Telomeric Sequence with TMPyP4 Porphyrine

Abstract

The model of the complex formation in a DNA oligonucleotide solution in the presence of TMPyP4 porphyrine has been recognized using a matrix method basing on the experimentally observed composition-property features. The experimental data on UV spectroscopic titration of G4 Tel22 oligonucleotide by TMPyP4 porphyrine have been interpreted in terms of equilibrium complex formation of the ligand with the macromolecule at four independent binding sites (coordination vacancies). The suggested matrix model has considered the mutual influence of the ligands bound at each of the Tel22 coordination vacancies. Sequential attachment of the TMPyP4 ligand to the Tel22(TMPyP4)_n complex has affected the shape of the UV absorption spectrum of the earlier bound ligands. The cross-validation of the conventional stepwise complex formation model and the matrix binding model has confirmed the validity of the new interpretation.