Departamento de Física, CEPAE, Universidade Federal de Goiás, 74690-900, Goiânia, GO, Brazil.
Phys Chem Chem Phys. 2021 Apr 14;23(14):8413-8425. doi: 10.1039/d1cp00183c. Epub 2021 Mar 25.
In this work, we observe the behavior of the dipole moment, atomic charges, solute-solvent interactions and NMR spectroscopy of aliphatic amino acids in a water solution via the computational simulations of classical molecular dynamics and DFT quantum calculations. Our results indicate that the convergence of the atomic charge of the solute, from an iterative process, together with the dipole moment of the amino acid, alters the lifetime of hydrogen bonds present in the first solvation shell, resulting in the modification of its structure and dynamics. Using GIAO-DFT-NMR calculations, we assessed the impact of these structural solute-solvent modifications on the magnetic shielding constants of the solute carbon atoms. In this sense, we evaluate the importance of an update in parameters that describe atomic charges present in the CHARMM36 force field.
在这项工作中，我们通过经典分子动力学模拟和 DFT 量子计算，观察了在水溶液中脂肪族氨基酸的偶极矩、原子电荷、溶剂-溶质相互作用和 NMR 光谱的行为。我们的结果表明，溶质原子电荷的收敛（来自迭代过程）与氨基酸的偶极矩一起改变了存在于第一溶剂化壳中的氢键的寿命，导致其结构和动力学的改变。使用 GIAO-DFT-NMR 计算，我们评估了这些结构-溶剂溶质修饰对溶质碳原子磁屏蔽常数的影响。在这种意义上，我们评估了更新 CHARMM36 力场中描述原子电荷的参数的重要性。
