del Carmen Fernández-Alonso María, Cañada Francisco Javier, Jiménez-Barbero Jesús, Cuevas Gabriel
Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain.
J Am Chem Soc. 2005 May 25;127(20):7379-86. doi: 10.1021/ja051020+.
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.
从理论和实验两个角度都证明了稳定的碳水化合物 - 芳香族相互作用的存在。通过使用MP2/6 - 31G(d,p)理论水平并在优化过程中考虑平衡校正，已正确解释了基于实验的半乳糖 - 凝集素复合物的几何结构。在这种情况下，岩藻糖 - 苯复合物的稳定相互作用能为3.0千卡/摩尔。本文获得的理论结果表明，碳水化合物 - 芳香族相互作用是具有重要色散成分的稳定相互作用，并且糖氢与芳香环之间确实存在电子密度，从而产生了三个所谓的非常规氢键。水溶液中的简单核磁共振实验也显示了芳香基团与某些糖相互作用的内在倾向的实验证据。苯和苯酚与β-甲基半乳糖苷α面的C - H键簇特异性相互作用，不需要蛋白质受体提供的明确三维形状，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。
