title: Evaluation of the hydrogen bond energy of base pairs formed between substituted 9-methyladenine derivatives and 1-methyluracil by use of molecular orbital theory.
abstract: Systematic substituent effects on the stability of the hydrogen bonding between substituted 9-methyladenine derivatives (Ax) and 1-methyluracil (U) were studied by ab initio molecular orbital theory. Predicted substituent effects on the hydrogen bond energies of Ax-U base pairs were in good agreement with those observed for experimental binding constants. Ab initio calculation is effective for evaluation of the stability of the hydrogen-bonding pairs of chemically modified nucleic acid base analogues. In contrast to the substitution effect of uracil on hydrogen bond energies of A-Ux base pairs, it is difficult to systematically interpret the substitution effect of adenine derivatives for Ax-U base pairs.
authors.affiliation: Department of Physical Chemistry, National Institute of Materials and Chemical Research, Agency of Industrial Science and Technology, MITI, Biomolecular Group, National Institute of Advanced Interdisciplinary Research, Tsukuba Science City, Ibaraki, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Kawahara
authors.forename: K
authors.initials: K
authors.lastname: Taira
authors.forename: M
authors.initials: M
authors.lastname: Sekine
authors.forename: T
authors.initials: T
authors.lastname: Uchimaru
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000737:chemistry*; D020029:Base Pairing; D015195:Drug Design; D004355:Drug Stability; D006860:Hydrogen Bonding; D008956:Models, Chemical; D015394:Molecular Structure; D012313:RNA / Q000737:chemistry*; D013816:Thermodynamics; D014498:Uracil / Q000031:analogs & derivatives* / Q000737:chemistry*
chemical_list: D014498:Uracil; C002596:1-methyluracil; D012313:RNA; C013115:9-methyladenine; D000225:Adenine