Probes of DNA Structure and Interactions: Effects of Copper II on Ultraviolet-Induced Pyrimidine Dimer Formation

B. M. Sutherland, J. C. Sutherland

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8 Scopus citations


Cu(II) affects the yield of cyclobutyl dimers induced in DNA by 254 nm radiation. The effects are a function of r, the ratio of Cu(II) to DNA phosphate, and of the ultraviolet (UV) fluence; they seem to reflect two types of copper complexes with DNA. The first probably involves “exterior” binding to the bases of native DNA and increases [unk]TT formation (without affecting [unk]UT yield) by raising the energy levels of bases other than thymine. The second seems to occur only at high ratios (rs) and only after the structure has been opened locally by UV radiation; it involves “interior” binding of Cu(II) to the bases. This complex tends to decrease dimer yield by holding the bases apart and/or by lowering the energy levels of bases other than thymine. These results illustrate the potential use of DNA photoproducts and ligands to probe the structure and interactions of DNA in vitro and perhaps also in vivo.

Original languageEnglish (US)
Pages (from-to)1329-1336
Number of pages8
JournalBiophysical Journal
Issue number11
StatePublished - Jan 1 1969
Externally publishedYes


ASJC Scopus subject areas

  • Biophysics

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