Department of Chemistry, Swedish University of Agricultural Sciences, Biocenter P.O. Box 7015, Uppsala SE-75007, Sweden.
Molecules. 2013 Aug 14;18(8):9735-54. doi: 10.3390/molecules18089735.
Trehalose, a well-known stress-protector of biomolecules, has been investigated for its effect on the mobility, hydration and hydrogen bond interaction of lactose using diffusion-ordered NMR spectroscopy and NMR of hydroxy protons. In ternary mixtures of trehalose, lactose and water, the two sugars have the same rate of diffusion. The chemical shifts, temperature coefficients, vicinal coupling constants and ROE of the hydroxy protons in trehalose, lactose and sucrose were measured for the disaccharides alone in water/acetone-d₆ solutions as well as in mixtures. The data indicated that addition of trehalose did not change significantly the strength of the hydrogen bond interaction between GlcOH3 and GalO5' in lactose. Small upfield shifts were however measured for all hydroxy protons when the sugar concentration was increased. The chemical shift of the GlcOH3 signal in lactose showed less change, attributed to the spatial proximity to GalO5'. Chemical exchange between hydroxy protons of lactose and trehalose was observed in the ROESY NMR spectra. Similar effects were observed with sucrose indicating no specific effect of trehalose at the concentrations investigated (73 to 763 mg/mL) and suggesting that it is the concentration of hydroxy groups more than the type of sugars which is guiding intermolecular interactions.
海藻糖是一种众所周知的生物分子应激保护剂，它对乳糖的流动性、水合作用和氢键相互作用的影响已通过扩散有序 NMR 光谱和羟基质子 NMR 进行了研究。在海藻糖、乳糖和水的三元混合物中，两种糖的扩散速度相同。在水/丙酮-d₆溶液中和混合物中，单独测量了海藻糖、乳糖和蔗糖中羟基质子的化学位移、温度系数、邻位耦合常数和 ROE。数据表明，添加海藻糖不会显著改变乳糖中 GlcOH3 和 GalO5'之间氢键相互作用的强度。然而，当糖浓度增加时，所有羟基质子的化学位移都出现了较小的向上移动。乳糖中 GlcOH3 信号的化学位移变化较小，这归因于与 GalO5'的空间接近。在 ROESY NMR 谱中观察到了乳糖和海藻糖的羟基质子之间的化学交换。在蔗糖中也观察到了类似的影响，这表明在研究浓度（73 至 763mg/mL）下，海藻糖没有特异性作用，这表明是羟基数目的浓度而不是糖的类型指导着分子间相互作用。
