Equilibrium binding of carcinogens and antitumor antibiotics to DNA: Site selectivity, cooperativity, allosterism Article

Winkle, SA, Krugh, TR. (1981). Equilibrium binding of carcinogens and antitumor antibiotics to DNA: Site selectivity, cooperativity, allosterism . NUCLEIC ACIDS RESEARCH, 9(13), 3175-3186. 10.1093/nar/9.13.3175

cited authors

  • Winkle, SA; Krugh, TR

authors

abstract

  • The equilibrium binding of the carcinogens N-hydroxy-N-acetyl-2-amino-fluorene (HAAF) and 4-nitroquinoline-l-oxide (NQO) to φ{symbol}X174RF DNA have been studied by phase partition techniques. Both molecules bind in a cooperative manner with only a few carcinogen molecules binding to each φ{symbol}X174RF DNA molecule. The binding data for both HAAF and NQO fit a model in which two carcinogens cluster into a small number of sites - four sites for HAAF and twelve sites for NQO. Phase partition techniques were also used to study the binding of actinomycin D to both calf thymus DNA and poly(dG-dC).poly(dG-dC) at much lower r values than had been previously reported. These data exhibit humped Scatchard plots which are indicative of cooperative binding; the overall shape of the Scatchard plots are consistent with a model for drug induced allosteric transitions in the DNA structure. The cooperativity in the actinomycin D binding to calf thymus DNA increases with decreasing sodium chloride concentration, suggesting a role for DNA flexibility in allosteric binding. © 1981 IRL Press Limited.

publication date

  • July 10, 1981

published in

Digital Object Identifier (DOI)

start page

  • 3175

end page

  • 3186

volume

  • 9

issue

  • 13