Why does cisplatin bind to ApG but not GpA sequences of DNA? A molecular mechanics analysis

Abstract

Molecular mechanics modelling of the bifunctional binding of cisplatin to d(GpApG): d(CpTpC) and d(GpGpA) : d(TpCpC) sequences shows that attachment to ApG sequence is favoured by 28 kJ mol^–1 over attachment to GpA sequences as a result of a favourable hydrogen bond between an ammine ligand and O⁶ of the 3′ guanine in the former case, and a highly unfavourable interaction between the ammine ligand and the amine group of the 3′ adenine in the latter.