The influence of dithiothreitol on DNA radiolysis in frozen aqueous solution: an EPR study

Abstract

The effect of a thiol, dithiothreitol (DTT), on DNA radiolysis at cryogenic temperatures was investigated by the EPR method. Dithiothreitol repairs up to 30% of DNA radicals, but an increase in the thiol concentration above 10 mM, even up to 1000 mM, does not further enhance the overall level of the repair process. The transfers of paramagnetic centres from both the guanine radical cation. and the allyl radical of thymine, to thiol were observed, while products generated via the reductive pathway remained unaffected. (C) 2002 Elsevier Science Ltd. All rights reserved