Chemical cross-linking of ethidium to DNA by glyoxal.
Ethidium was found to be efficiently cross-linked to DNA by glyoxal. Kinetic studies showed that the rate of the cross-linking reaction is strongly dependent on the glyoxal concentration. Comparative studies using a series of phenanthridines and acridines showed that NH2 groups at both the 2 and 7 positions on the phenanthridine ring are necessary for efficient cross-linking. Studies using synthetic polydeoxynucleotides showed that the 2-amino group of guanine is absolutely required for cross-linking. Fluorescence contact energy transfer and relative viscosity experiments showed that the cross-linked drug remains intercalated into DNA. DNA gel electrophoresis and melting studies demonstrated that cross-linked ethidium does not dissociate the DNA double helix to single strands.
Department of Biochemistry, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216-4505, USA.
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Chaires
D000818:Animals; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D004996:Ethidium / Q000737:chemistry*; D005399:Fishes; D005453:Fluorescence; D006037:Glyoxal / Q000737:chemistry*
D003432:Cross-Linking Reagents; D006037:Glyoxal; D004247:DNA; D004996:Ethidium