Oddziaływanie elektronów z cząsteczkami o biologicznym znaczeniu

Recent years have witnessed an increase of the interest in the studies of the interaction of electrons with biologically relevant molecules. This has been mainly motivated by the seminal work, where it has been demonstrated that low energy electrons can induce single and double strand breaks in DNA in the energy range below the level of ionization. Since the damage profile as a function of electron energy showed pronounced resonances it was proposed that resonant electron capture could occur at particular molecular components of the DNA as the initial step towards strand breaks. From a series of experiments on electron attachment to DNA building blocks (nucleobases, the sugar moiety and the phosphate unit) became obvious that they effectively capture electrons leading to the formation of low energy resonances associated with the decomposition of the corresponding molecule. Recent dissociative electron attachment experiments on an entire gas phase nucleotide 2’-deoxycytidine-5´-monophosphate give also insight into the molecular mechanism involved, which comprises both direct electron attachment to the backbone and transfer of the excess electron from cytosine to the backbone resulting in single strand breaks. The results further allow an estimate of the relative contribution of these different mechanisms to single strand breaks.