Abstract:
:Incubation of O6-[3H]ethylguanine-containing DNA with a rat liver chromatin fraction resulted in a decrease in the O6-ethylguanine content of the DNA. Analysis of the products of this reaction showed that the ethyl group had been transferred from the O6-ethylguanine to a protein acceptor. When the incubation mixture was separated on a cesium chloride gradient, the radioactivity removed from O6-ethylguanine appeared in a low-density band. This material has been isolated and subjected to trypsin digestion and high-pressure liquid chromatography analysis; it was sensitive to trypsin and the digest contained new high-pressure liquid chromatography peaks characteristic of oligopeptides. Radioactive peaks from the trypsin digestion have been digested further to the amino acid level and have been shown to contain S-[3H]ethylcysteine. Thus, we conclude that the repair activity in rat liver chromatin removes the ethyl group from O6-ethylguanine and transfers it to a cysteine moiety contained in an acceptor protein.
journal_name
Proc Natl Acad Sci U S Aauthors
Mehta JR,Ludlum DB,Renard A,Verly WGdoi
10.1073/pnas.78.11.6766subject
Has Abstractpub_date
1981-11-01 00:00:00pages
6766-70issue
11eissn
0027-8424issn
1091-6490journal_volume
78pub_type
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