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Title: Effect of ionic strength and cationic DNA affinity binders on the DNA sequence selective alkylation of guanine N7-positions by nitrogen mustards

Journal Article · · Biochemistry; (USA)
DOI:https://doi.org/10.1021/bi00464a014· OSTI ID:6318311
; ;  [1]
  1. Univ. College and Middlesex School of Medicine, London (England)

Large variations in alkylation intensities exist among guanines in a DNA sequence following treatment with chemotherapeutic alkylating agents such as nitrogen mustards, and the substituent attached to the reactive group can impose a distinct sequence preference for reaction. In order to understand further the structural and electrostatic factors which determine the sequence selectivity of alkylation reactions, the effect of increase ionic strength, the intercalator ethidium bromide, AT-specific minor groove binders distamycin A and netropsin, and the polyamine spermine on guanine N7-alkylation by L-phenylalanine mustard (L-Pam), uracil mustard (UM), and quinacrine mustard (QM) was investigated with a modification of the guanine-specific chemical cleavage technique for DNA sequencing. The result differed with both the nitrogen mustard and the cationic agent used. The effect, which resulted in both enhancement and suppression of alkylation sites, was most striking in the case of netropsin and distamycin A, which differed from each other. DNA footprinting indicated that selective binding to AT sequences in the minor groove of DNA can have long-range effects on the alkylation pattern of DNA in the major groove.

OSTI ID:
6318311
Journal Information:
Biochemistry; (USA), Vol. 29:12; ISSN 0006-2960
Country of Publication:
United States
Language:
English