title: NMR imino proton exchange experiments on duplex DNA primarily monitor the opening of purine bases.
abstract: Molecular dynamics simulations were performed to investigate GC and AT base opening events in DNA. Calculated equilibrium constants between the base open (or flipped) and closed states were shown to be in good agreement with experimental data from NMR imino proton exchange experiments. Analysis of the computed results indicates that the equilbrium constants are dominated by the opening of the A and G bases in the AT and GC base pairs, respectively. Thus, the present results predict that NMR imino proton exchange experiments of base opening are primarily monitoring the opening of purine bases.
authors.affiliation: Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201, USA.
authors.forename: U Deva
authors.initials: UD
authors.lastname: Priyakumar
authors.forename: Alexander D
authors.initials: AD
authors.lastname: Mackerell
mesh_terms: D000225:Adenine / Q000737:chemistry; D020029:Base Pairing; D004247:DNA / Q000737:chemistry*; D007700:Kinetics; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D009690:Nucleic Acid Conformation; D011687:Purines / Q000737:chemistry*; D013816:Thermodynamics; D013866:Thioguanine / Q000737:chemistry
chemical_list: D011687:Purines; D004247:DNA; D013866:Thioguanine; D000225:Adenine