UV-induced DNA self-repair mechanism traced with quantum chemistry

Sebastian Reiter,Daniel Keefer,Vitus Besel,Regina De Vivie‐Riedle

doi:10.1051/epjconf/201920509024

Sebastian Reiter, Daniel Keefer + Show 2 more

Open Access

https://doi.org/10.1051/epjconf/201920509024

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Abstract

Recently, UV radiation was found to promote the self-repair of a damaged DNA nucleobase sequence. The proposed mechanism after photoexcitation of an adjacent guanine adenine sequence is now validated by our quantum chemical calculations.

Highlights

The first step of the proposed photochemically initiated self-repair of the cyclobutane pyrimidine dimer (CPD) lesion involves the formation of G-A exciplexic states
They found that excitation of G leads to repair of the CPD lesion and claim a long-living (300 ps) charge-transfer state between G and A, followed by electron transfer from A to the CPD to be responsible for the repair
With the tools of state of the art quantum chemistry (QC), we investigate this mechanism by inspecting the possibilities of exciplex formation and the character and energetic profile of the excited states that can be reached with the experimentally applied UV excitation at 290 nm

Summary

Introduction

The first step of the proposed photochemically initiated self-repair of the CPD lesion involves the formation of G-A exciplexic states. A recent experimental study discovered that UV radiation can damage genetic material and promote self-repair of defective nucleobase sequences [3]. They found that excitation of G leads to repair of the CPD lesion and claim a long-living (300 ps) charge-transfer state between G and A, followed by electron transfer from A to the CPD to be responsible for the repair.

Results

Conclusion