8-HYDROXYGUANINE IS NOT PRODUCED BY PERMANGANATE OXIDATION OF DNA

Single-stranded M13mp2 DNA was oxidized with 0.8 mM KMnO4 at pH 8.6 an d 4 degrees C for 5 min. These are conditions used previously by Akman ct al. (Arch. Biochem. Biophys., 1990, 282, 202) for the oxidation of a denatured DNA and the authors reported that 8-hydroxy-guanine was f ormed in the DNA with this treatment. We decomposed the oxidized DNA w ith heating in formic acid and the resulting bases were analyzed by HP LC. No significant 8-hydroxyguanine formation was detected in this sam ple. We also investigated the consumption of KMnO4 by nucleosides. Und er conditions in which thymidine consumed KMnO4 rapidly, very little c onsumption was found with deoxyguanosine (less than 1/100, in rate, co mpared to that by thymidine). These results show that the permanganate oxidation of DNA does not result in the formation of 8-hydroxyguanine . (C) 1994 Academic Press, Inc.