||Quantum Mechanism of Its Radiation Sensitizing
Study of Electronic Property of Halogenated DNA
Onizawa, Misato ,
Haga, Yoshinori ,
Tanaka, Shigenori ,
Koibuchi, SeiyaYokoya, Akinari
The aim of this study is to elucidate the mechanism of radiosensitization by halogenated pyrimidines from the point of view of electronic state of DNA, which might show a characteristic like half metal around the halogenated site. To address this subject, we measured specific heat capacity of a single crystal of bromiouracil (BrU) under ultralow temperature, and found that it was obviously higher than that of non-halogenated pyrimidine (thymine), indicating that the number of microscopic states increases with the halogen-substitution. We have also tried to prepare plasmid DNA in which certain fraction of thymine was replaced with bromouracil to measure the radiation effects, such as induction of molecular damage of double strand breaks in the DNA. Preliminary results indicate that double strand breaks increase approximately 20% in the halogenated plasmid compared to normal one. In the present poster, these evidences will be discussed in terms of the electric states of the halogenated DNA.