Taras Shevchenko National University of Kyiv, Faculty of Physics, 4 Hlushkova Prosp., Kyiv 03022, Ukraine.
J Biomol Struct Dyn. 2011 Dec;29(3):563-75. doi: 10.1080/07391102.2011.10507406.
Relaxed force constants (RFCs) and vibrational root-mean-square deviations have been evaluated by the original calculation method for conformational parameters of the DNA structural units and their constituents: nucleic acid bases (uracile, thymine, cytosine, adenine and guanine) and their 'building blocks' (benzene, pyrimidine, imidazole and purine molecules), as well as the DNA backbone structural units: tetrahydrofuran, 1,2-dideoxyribose, methanol and orthophosphoric acid. It has been found that the RFCs for nomenclature torsions beta, gamma, epsilon; and sugar pseudorotation angle P in 1,2-dideoxyribose are sensible to the molecule conformation and their values are in the range of 1-25 kcal/(mole·rad²) obeying the inequality K(γ)> K(ε) > K(ρ) > K(β). The RFCs values for endocyclic torsions of nucleic acid bases six-member rings lie within 15-45 kcal/(mole·rad²) in pyrimidines and within 20-60 kcal/(mole·rad²) in purines. It is shown that the quantum zero-point motion effectively neglects the amino group non-planarity in cytosine, adenine and partially in guanine.
已通过 DNA 结构单元及其组成部分（核酸碱基（尿嘧啶、胸腺嘧啶、胞嘧啶、腺嘌呤和鸟嘌呤）及其“构建块”（苯、嘧啶、咪唑和嘌呤分子），以及 DNA 骨架结构单元：四氢呋喃、1,2-二脱氧核糖、甲醇和正磷酸）的构象参数的原始计算方法，评估了松弛力常数（RFC）和振动均方根偏差。发现 1,2-二脱氧核糖中命名扭转β、γ、ε和糖假旋转角 P 的 RFC 对分子构象敏感，其值在 1-25 kcal/（摩尔·拉德²）范围内，满足不等式 K(γ)> K(ε) > K(ρ) > K(β)。核酸碱基六元环中环内扭转的 RFC 值嘧啶内为 15-45 kcal/（摩尔·拉德²），嘌呤内为 20-60 kcal/（摩尔·拉德²）。结果表明，量子零点运动有效地忽略了胞嘧啶、腺嘌呤和部分鸟嘌呤中氨基的非平面性。
