Figure 5
From: Reduced repair of 8-hydroxyguanine in the human breast cancer cell line, HCC1937
Stimulation of 8-OH-Gua-specific incision activity of HCC1937 nuclear extracts by purified OGG1. HCC1937 nuclear extracts (50 μg) were incubated with a 5' end-labeled oligonucleotide containing a single 8-OH-Gua in the presence of increasing amounts of hOGG1 for 1 h. Reactions were stopped and the products separated by electrophoresis through 20% polyacrylamide gels containing 7 M urea. The band images were analyzed by PhosphorImager and quantified using ImageQuant software. Panel A, a representative gel image showing the incision reaction products, panel B, quantified results of the incision reaction products. One-way ANOVA revealed a statistically significant difference of p < 0.002 (*) in the stimulation of activity by purified hOGG1. A unit of hOGG1 catalyzes the cleavage of 1 picomole of a duplex 32P-labeled oligonucleotide in 1 h at 37°C at 8-OH-Gua/C base pair.