Characterization of a novel reaction by human O6-alkylguanine-DNA alkyltransferase with 1,3-bis(2-chloroethyl)-1-nitrosourea-treated DNA.
The reaction of partially purified human O6-alkylguanine-DNA alkyltransferase with 1,3-bis(2-chloroethyl)-1-nitrosourea-treated DNA produces a covalent DNA-protein complex. Evidence that the complex-forming and the alkyltransferase activities are one and the same includes their copurification, identical heat inactivation kinetics, and similar responses to inhibitors. This novel reaction thus provides a sensitive alternative assay for detecting the alkyltransferase. It also provides support for a model in which N1,O6-ethanoguanine is an intermediate in formation of chloroethylnitrosourea-induced DNA interstrand cross-links.
Brent
T P
TP
Department of Biochemical and Clinical Pharmacology, St. Jude Children's Research Hospital, Memphis, Tennessee 38101.
Remack
J S
JS
Smith
D G
DG
D002330:Carmustine / Q000494:pharmacology*; D055598:Chemical Phenomena; D002621:Chemistry; D004247:DNA / Q000187:drug effects* / Q000378:metabolism; D006358:Hot Temperature; D006801:Humans; D007700:Kinetics; D008780:Methyltransferases / Q000378:metabolism*; D019853:O(6)-Methylguanine-DNA Methyltransferase
D004247:DNA; D008780:Methyltransferases; D019853:O(6)-Methylguanine-DNA Methyltransferase; D002330:Carmustine