Stm Studies of Hydrogen-bonded Dna Base Aggregates Relevant for Biology

Hydrogen bonding between DNA bases is one of the main interactions that control the conformation and hence the biochemical function of nucleic acid molecules [1]. The exact physico-chemical nature of these bonds, and the importance of charge transfer contribution to the stabilization energy associated to hydrogen bonding in NA molecules have recently been the subject of an intense debate [2-4], motivated by the discovery that a hydrogen bond formation is not necessary for the specificity in DNA replication [5]. Experiments to quantify the charge transfer associated with hydrogen bonding between nucleic acid bases are nevertheless difficult to design and interpret for systems consisting of DNA and RNA molecules in buffer solution.