Figure 4. Comparison of the site specificity of DNA cleavage induced by histone H1-hydroperoxides and AAPH.

Reaction mixtures containing the ³²P-5′-end-labelled 443 bp DNA fragment, calf thymus DNA (20 μM in DNA bases), 0.7 μM histone H1-hydroperoxides and 20 μM Cu(I) (A), 1 mM AAPH (B) or 0.7 μM histone H3-hydroperoxides and 20 μM Cu(I) (C) in 200 μl of 10 mM sodium phosphate buffer (pH 7.4) containing 5 μM DTPA were incubated at 37 °C for 60 min. After Fpg treatment, the DNA fragments were analysed by the method described in Figure 3.