Effect of High-Energy Proton and Gamma Irradiation on the Structure of DNA in Solutions

A comparative study is performed of damage to the structure of DNA under the action of radiation with identical LET = 0.3 keV µm −1 (gamma radiation and protons with an energy of 1 GeV at absorbed doses of 0–100 Gy in 5 and 150 mM NaCl solutions). It is found that proton irradiation results in a smaller drop in the DNA’s melting temperature than gamma irradiation. Defects in the secondary structure of DNA are greater in solutions irradiated with gamma rays. Signs of local multiple damage are observed in DNA irradiated with protons. It is found that proton irradiation has a more lethal effect than gamma irradiation.