Extracts from various rat tissues were incubated with [3H]methylated DNA or chromatin in order to compare their abilities to catalyze the removal of labeled O6-methylguanine from acid precipitable DNA. Liver extracts had the greatest activity. Kidney extracts had about 35% of the activity in liver and extracts from lung, colon, small intestine and brain were much less active. The enzyme responsible for this reaction does not appear to be an N-glycosidase because no labeled O6-methylguanine could be detected in the supernatant fraction even though more than 50% of this base was lost from the DNA. The released radioactivity was present as methanol which is consistent with the possibility that the reaction may involve a demethylase action on either the DNA substrate or an oligonucleotide derived from it.
|Original language||English (US)|
|Number of pages||8|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Sep 14 1978|
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology