DNA bird's ostrich oxidation damages the fundamental reaction pathway in the free-base ion-to-intermediate.

The oxidation properties of the Ostrich G base are very active and play an important role in the process of DNA oxidation damage and DNA charge conduction.
In the action of light or strong oxidation freebies, the G base easily loses an electron to form a cation free substation (G?), triggering cavitation transmission on the DNA strand or a series of DNA oxidation damage reactions to produce subsequent damage products (8-OG, FAPY-G, imidazolone, oxazolone, etc.).
With the support of the National Natural Science Foundation of China, the Ministry of Science and Technology, and the Chinese Academy of Sciences, researchers in the Key Laboratory of Photochemistry of the Institute of Chemistry of the Chinese Academy of Sciences are committed to developing time-resolution laser spectroscopy methods to study in depth the complex processes and processes of DNA oxidation damage series reactions.
For single electron oxidation and de-proton reactions of G-bases in the secondary structure G-four-chain system of DNA, the researchers detected that cation free-based G-plus differs from individual base dG and dual-stranded DNA in the unique de-proton reaction pathway (deamino-proton N2-H instead of sub-Amino proton N1-H), which reveals the effect of local hydrogen bond microencer environment of DNA structure on proton transfer reaction, and describes the dynamic microscopic process of G-tetrahynamic telomere DNA oxidation damage (J.Am.Chem.Soc.2015, 137,259-266).
the previous work, the researchers further detected the key reaction intermediates of DNA oxidation damage.
the generation of cation free-based G-plus, which causes oxidative damage reaction, is not simply a direct single electron oxidation process, but often involves a class of important free-based ions participating in the reaction of intermediates.
the theoretical calculation predicts that free-fundamental ions have a short life on the intermediates and are extremely low in stability, which has been difficult to detect in past experiments.
recently, researchers successfully captured free-fundamental ion-to-intermediates in the pathway of DNA ostrich oxidation damage by means of low-temperature stable reaction intermediates and combined with time-resolution spectral detection.
the reaction system of chlorine free base and G base, the strong absorption peak with center at 570nm was detected on the low temperature transient absorption spectrum, and the theoretical calculation was attributed to G.... Cl-ion-to-intermediate, the characteristic absorption spectrum of this visible light region, is caused by the overlap of ion-to-static changes in the leap orbital space, and the study gives spectral characteristics that can be used to distinguish ion-to-intermediates from other transient species such as G.
the researchers further observed in the oxidation reaction system of double-stranded DNA that the ion-to-intermediate characteristic spectral splits at 570nm were divided into 480nm and 610nm absorption peaks.
with the help of dynamic analysis, it is determined that the two absorption peaks correspond to the two ion-to-structural Cl, which correspond to the balance of the two-chain GC base-to-internal proton transfer-... G:C↔Cl-... G(-H) : C (-H), through the split of the ion-to-feature spectrum, clearly distinguishes the two protonized structures of the double-stranded DNA base to the internal proton transfer balance, and measures the reaction power of proton transfer (Ea-1.4 kcal/mol).
these results give the key experimental evidence of the free-based ions of DNA bird's ostrich oxidation reaction, which is of great significance for the deep understanding of the processes of DNA proton coupling electron transfer and DNA oxidation damage.
results of the study were published in Science Advances (Sci.Adv.2017, 3, e1700171.) on.
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