Figure 7.

EcoRI cleavage following reduction of the cross-link. ³²P-radiolabeled γ-HOPdG-modified substrate or unmodified substrate (500 nM) was incubated with EcoRI (5 nM) in the absence of Mg²⁺ and either the presence or the absence of NaCNBH₃ for 2 h. Following preincubation, MgCl₂ (10 mM) was added to initiate cleavage. Reactions were incubated at 37 °C for various times. Cleavage profiles shown are for the 21-mer strand of the DNA duplex. Unmodified substrate, −NaCNBH₃ (◼); unmodified substrate, +NaCNBH₃ (◻); γ-HOPdG-modified substrate, −NaCNBH₃ (●); and γ-HOPdG-modified substrate, +NaCNBH₃ incubation (○).