Electrochemical behavior of natural and biosynthetic polynucleotides at the pyrolytic graphite electrode A new probe for studies of polynucleotide structure and reactions

The electrochemical oxidation of natural and biosynthetic polynucleotides at a pyrolytic graphite electrode (PGE) has been studied under differential pulse voltammetric conditions. Denatured DNA, ribosomal and transfer RNA give two voltammetric peaks. The first (more negative peak, peak G) corresponds to electrochemical oxidation of guanine residues where-as the second, more positive peak (peak A) corresponds to electrochemical oxidation of adenine residues. Native DNA gives rise only to a small peak A, peak G being totally absent. Denatured DNA and its voltammetric oxidation product are both strongly adsorbed at the PGE. Differential pulse voltammetric oxidation of natural and biosynthetic polynucleotides may provide a valuable technique for probing A-T and G-C regions during structural and conformational changes of these molecules and for following their interactions with other solution species.