Cooke R M, Hale R S, Lister S G, Shah G, Weir M P
Department of Biomolecular Structure, Glaxo Research and Development, Greenford, Middlesex, U.K.
Biochemistry. 1994 Sep 6;33(35):10591-6. doi: 10.1021/bi00201a004.
High-field NMR spectroscopy has been used to study the complex formed by the tetrasaccharide sialyl Lewis X and its receptor, E-selectin. Transferred NOEs demonstrate a specific interaction between the protein and ligand and enable measurement of the dissociation constant for the complex to be between approximately 1.1 and 2.0 mM. Differences between Overhauser spectra for free and bound sialyl Lewis X highlight a conformational change upon binding. This can be pinpointed to a change in the torsion angle of the glycosidic link between the sialyl and galactosyl residues and used to select a likely "bound" conformation from four low-energy species. Docking the bound form of sialyl Lewis X onto a model of the lectin domain of E-selectin suggests that the conformational change upon binding results primarily from steric interactions.
高场核磁共振光谱已被用于研究四糖唾液酸化路易斯X与其受体E-选择素形成的复合物。转移核Overhauser效应（NOE）表明蛋白质与配体之间存在特异性相互作用，并能够测量该复合物的解离常数在约1.1至2.0 mM之间。游离和结合的唾液酸化路易斯X的奥弗豪泽光谱之间的差异突出了结合时的构象变化。这可以精确到唾液酸基和半乳糖基残基之间糖苷键扭转角的变化，并用于从四种低能构象中选择一种可能的“结合”构象。将唾液酸化路易斯X的结合形式对接至E-选择素凝集素结构域的模型表明，结合时的构象变化主要是由空间相互作用引起的。
