Franz Andreas H, Bromley Kendall S, Aung Ei T, Do Stephen Q L, Rosenblatt Hana M, Watson Amelia J
Department of Chemistry, University of the Pacific, Stockton, California, USA.
Magn Reson Chem. 2025 Jan;63(1):3-16. doi: 10.1002/mrc.5483. Epub 2024 Oct 16.
The quantitative solution conformations of 2-(hydroxymethyl)-tetrahydropyran, α-methyl-d-mannopyranoside, and 6-[α-d-mannopyranosyl]-d-mannopyranose (mannobiose) are described. Parametrized Karplus equations for redundant spin pairs across the terminal ω-torsion and the glycosidic ω-torsion for mannobiose are developed, including ω/θ-hypersurfaces for the terminal hydroxymethylene group. Experimental NMR data, algorithmic spectral simulation (clustered Hamiltonian method), molecular dynamics (MD) simulations (GLYCAM06), energy minimizations by DFT, and adjusted torsion angle populations weighted over the Karplus-type equations are used. We demonstrate that spectral simulation is a powerful tool in the refinement of initial J values obtained from static GAIO DFT calculations. We also show that only as few as one of multiple redundant torsions can be diagnostic for conformational analysis of the disaccharide.
描述了2-(羟甲基) - 四氢吡喃、α - 甲基 - d - 甘露吡喃糖苷和6 - [α - d - 甘露吡喃糖基] - d - 甘露吡喃糖（甘露二糖）的定量溶液构象。开发了用于甘露二糖末端ω扭转和糖苷ω扭转的冗余自旋对的参数化Karplus方程，包括末端羟亚甲基基团的ω/θ超曲面。使用了实验核磁共振数据、算法光谱模拟（聚类哈密顿方法）、分子动力学（MD）模拟（GLYCAM06）、密度泛函理论（DFT）的能量最小化以及基于Karplus型方程加权的调整扭转角种群。我们证明光谱模拟是细化从静态GAIO DFT计算获得的初始J值的有力工具。我们还表明，对于二糖的构象分析，多个冗余扭转中仅有一个就可以具有诊断性。
