Institut für Physikalische und Theoretische Chemie, Universität Regensburg, 93040 Regensburg, Germany.
G. A. Krestov Institute of Solution Chemistry, Russian Academy of Sciences, Kademicheskaya st. 1, 153045 Ivanovo, Russian Federation.
Phys Chem Chem Phys. 2021 Nov 17;23(44):25086-25096. doi: 10.1039/d1cp03543f.
The hydration and Cl ion binding of the neurotransmitter acetylcholine (ACh) and its synthetic analogue, carbamoylcholine (CCh), were studied by combining dilute-solution conductivity measurements with dielectric relaxation spectroscopy and statistical mechanics calculations at 1D-RISM and 3D-RISM level. Chloride ion binding was found to be weak but not negligible. From the ∼30 water molecules coordinating ACh and CCh only ∼1/3 is affected in its rotational dynamics by the cation, with the majority - situated close to the hydrophobic moieties - only retarded by a factor of ∼2.5. At vanishing solute concentration cations and the ∼3-4 HO molecules hydrogen bonding to the CO group of the solute exhibit similar rotational dynamics but increasing concentration and temperature markedly dehydrates ACh and CCh.
通过结合稀溶液电导率测量、介电弛豫光谱和 1D-RISM 和 3D-RISM 水平的统计力学计算，研究了神经递质乙酰胆碱 (ACh) 及其合成类似物氨基甲酰胆碱 (CCh) 的水合和 Cl 离子结合情况。发现氯离子结合较弱，但并非可以忽略不计。在与 ACh 和 CCh 配位的约 30 个水分子中，只有约 1/3 的水分子的旋转动力学受到阳离子的影响，而大部分水分子 - 靠近疏水性部分 - 仅被延迟约 2.5 倍。在溶质浓度为零时，阳离子和与溶质的 C-O 基团氢键结合的约 3-4 个 HO 分子表现出相似的旋转动力学，但随着浓度和温度的升高，ACh 和 CCh 明显脱水。
