title: DNA sequence specificity of guanine N7-alkylations for a series of structurally related triazenes.
abstract: The base sequence selectivity for reaction at the guanine-N7 position was examined for a series of structurally related triazenes by a modification of a standard DNA sequencing method. The monomethyl and monochloroethyl triazenes alkylate guanines extensively at the N7 position with a general preference for runs of contiguous guanines, similar to, but not as striking as that observed previously for the chloroethylnitrosoureas. In contrast to the nitrosoureas, the triazenes had patterns of base sequence selectivity that differed somewhat from agent to agent, with the monochloro-ethylphenyltriazene having the pattern most different from the others in the series. Thus, the nature of the nonalkylating portion of the molecule can influence the ultimate alkylation preference. The monoethylating analogues alkylated weakly with little sequence preference, and the dimethyl analogues were essentially unreactive in this system.
authors.affiliation: Laboratory of Molecular Pharmacology, National Cancer Institute, Bethesda, MD 20892.
authors.forename: J A
authors.initials: JA
authors.lastname: Hartley
authors.forename: W B
authors.initials: WB
authors.lastname: Mattes
authors.forename: K
authors.initials: K
authors.lastname: Vaughan
authors.forename: N W
authors.initials: NW
authors.lastname: Gibson
mesh_terms: D000478:Alkylation; D001483:Base Sequence; D004247:DNA; D004262:DNA Restriction Enzymes; D011905:Genes, ras; D006147:Guanine; D006801:Humans; D008969:Molecular Sequence Data; D013329:Structure-Activity Relationship; D014226:Triazenes
chemical_list: D014226:Triazenes; D006147:Guanine; D004247:DNA; D004262:DNA Restriction Enzymes