초록 |
Guanine is the most strongly oxidized base in the DNA, and generation of a guanine radical cation (G•+) as an intermediate in the oxidation reaction leads to migration of a resulting cationic hole through the DNA pi-stack until it is trapped by irreversible reaction with water or other free radicals. The charge transfer mechanism suggests that hotspots of oxidative DNA damage induced by electron transfer reagents can be predicted based on the primary DNA sequence. Consequently, CO3 radical may easy to migrate on other single G in the charge re-distribution step. However, there are strongly depend on the AP site in the cleavage patterns of Guanine oxidations by oxidizing agents with bulky physical size molecules such as BPT and Riboflavin. These radicals show strong AP site dependency on the oxidative damage along with clear G-site selectivity. |