Molecular recognition of saccharides by proteins. Insights on the origin of the carbohydrate-aromatic interactions
Molecular recognition of saccharides by proteins. Insights on the origin of the carbohydrate-aromatic interactions
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DOI：
10.1021/ja051020
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发表时间：
2005-05-25
影响因子：
15
通讯作者：
Cuevas, G
中科院分区：
文献类型：
--
作者：
Fernández, MD;Cañada, FJ;Cuevas, G
从理论和实验的角度都证明了稳定碳水化合物-芳香族相互作用的存在。通过使用 MP2/6-31G(d,p) 水平的理论并考虑优化过程中的平衡校正，可以正确解释基于实验的半乳糖-凝集素复合物的几何形状。在这种情况下，岩藻糖-苯络合物的稳定相互作用能达到3.0 kcal/mol。本文获得的理论结果表明，碳水化合物-芳香族相互作用是与重要分散组分的稳定相互作用，并且糖氢和芳香环之间确实存在电子密度，从而产生三个所谓的非常规氢键。水溶液中简单的核磁共振实验也证明了芳香族部分与某些糖相互作用的内在趋势的实验证据。苯和苯酚与甲基β-半乳糖苷的α面的C-H键簇发生特异性相互作用，不需要蛋白质受体提供明确的三维形状，因此类似于许多碳水化合物-蛋白质复合物中经常观察到的分子识别特征。
The existence of stabilizing carbohydrate-aromatic interactions is demonstrated from both the theoretical and experimental viewpoints. The geometry of experimentally based galactose-lectin complexes has been properly accounted for by using a MP2/6-31G(d,p) level of theory and by considering a counterpoise correction during optimization. In this case, the stabilizing interaction energy of the fucose-benzene complex amounts to 3.0 kcal/mol. The theoretical results obtained herein indicate that the carbohydrate-aromatic interactions are stabilizing interactions with an important dispersive component and that electronic density between the sugar hydrogens and the aromatic ring indeed exists, thus giving rise to three so-called nonconventional hydrogen bonds. Experimental evidence of the intrinsic tendency of aromatic moieties to interact with certain sugars has also been shown by simple NMR experiments in water solution. Benzene and phenol specifically interact with the clusters of C-H bonds of the alpha face of methyl beta-galactoside, without requiring the well-defined three-dimensional shape provided by a protein receptor, therefore resembling the molecular recognition features that are frequently observed in many carbohydrate-protein complexes.