The kinetics of degradation of DNA and RNA by H 2O 2

Abstract

Changes in primary and secondary structure of DNA in the presence of H 2O 2 have been examined. Base destruction was found to be the most important event. The apparent rate of base destruction was found to be 20.1 bases/h of the original molecule at 37°C in 0.088 M H 2O 2. The relative magnitude of other reaction rates were: base destruction > single-strand breaks > double-strand breaks > cross-linking. Denatured DNA was observed to be more sensitive to base destruction than native DNA. RNA base destruction rates exceeded those for DNA by a factor of three or more. CuCl 2 increased the rates of base destruction by H 2O 2, FeCl 2 had little effect and MgCl 2 decreased the rates.