On the effect of low-energy electron induced DNA strand break in aqueous solution: a theoretical study indicating guanine as a weak link in DNA.
In this theoretical study we have investigated the effect of low-energy electrons attached onto a 3'-guanine monophosphate, 3'-GMP, in the gas phase and in aqueous solution. DFT calculations with B3LYP/DZP++ were performed to study the C3'-O3' bond break of a 3'-GMP radical anion. Our results show that low-energy electrons, if attached to a 3'-GMP with a neutrally charged phosphate group, can easily induce a C3'-3' bond break in both the gas phase and aqueous solution. The activation energy was found here to be 10.3 kcal/mol in the gas phase and, even lower, 5.3 kcal/mol in aqueous solution. In comparison with calculated activation energies for other nucleotides the 3'-GMP has the lowest energy barrier in aqueous solution.
Schyman
Patric
P
Division of Physical Chemistry, Arrhenius Laboratory, Stockholm University, 106 91 Stockholm, Sweden. patric@physc.su.se
Laaksonen
Aatto
A
D004247:DNA / Q000737:chemistry*; D004249:DNA Damage; D004583:Electrons; D006147:Guanine / Q000031:analogs & derivatives / Q000737:chemistry*; D006157:Guanosine Monophosphate / Q000737:chemistry; D008958:Models, Molecular; D012996:Solutions; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
D012996:Solutions; D014867:Water; D006147:Guanine; D006157:Guanosine Monophosphate; D004247:DNA