Computer simulation of 57Fe bleomycin auger effects in DNA.
The antibiotic bleomycin binds to the DNA and induces double strand breaks (DSBs). To increase the cleavages. 57Fe is used to form a complex suitable for Mössbauer effect. The de-excitation of the resonant excited 57Fe nucleus releases Auger electrons and X rays. The goal of this work is to evaluate the increase in yield of DSBs due to the 57Fe, using Monte Carlo simulation methods. Particles spectra and the yields of single strand breaks (SSBs) and DSBs were calculated by considering direct events on DNA and reaction of all radical species generated in the radiolysis of its environment. The Auger spectrum shows a large number of electrons with energies below 100 eV, mainly responsible for direct damage, while another group around 600-700 eV is responsible for indirect damage effects. Bleomycin receives about one fourth of the energy deposited in DNA and an average of 0.65 DSB per de-excitation is observed.
CPAT, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse, France. terrissol@cpat.ups-tlse.fr
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Terrissol
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Pomplun
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Martin
D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D001761:Bleomycin / Q000494:pharmacology*; D003198:Computer Simulation; D004247:DNA / Q000187:drug effects / Q000528:radiation effects*; D004583:Electrons; D007503:Iron Isotopes; D009010:Monte Carlo Method
D000903:Antibiotics, Antineoplastic; D007503:Iron Isotopes; D001761:Bleomycin; D004247:DNA