Siebert H C, Gilleron M, Kaltner H, von der Lieth C W, Kozár T, Bovin N, Korchagina E Y, Vliegenthart J F, Gabius H J
Institut für Physiologische Chemie, Tierärztliche Fakultät, Ludwig-Maximilians-Universität, München, Germany.
Biochem Biophys Res Commun. 1996 Feb 6;219(1):205-12. doi: 10.1006/bbrc.1996.0206.
The binding of a carbohydrate to a lectin may affect the conformation of the ligand. To address this question for the galectin from chicken liver, the conformation of Gal beta 1-2Gal beta 1-R was analyzed in the free and in the galectin-bound state with 2D-ROESY- and 1D- as well as 2D-transferred NOE-experiments. A computer-assisted analysis of spatial parameters of the ligand by molecular dynamics (MD) and random walk molecular mechanics (RAMM) calculations, taking different dielectric constraints from epsilon = 1 to epsilon = 80 and various force fields into account, were instrumental to define the energetic minima of the free state. NMR-derived interresidual distance constraints enabled a conformational mapping. The two overlapping interresidual distance constraints obtained from transferred-NOE experiments of the galectin-ligand complex clearly support the notion that the conformation of the disaccharide in the bound state is at least very close to its global energy minimum state in solution.
碳水化合物与凝集素的结合可能会影响配体的构象。为了解决鸡肝半乳糖凝集素的这一问题，采用二维旋转核Overhauser效应光谱（2D-ROESY）、一维以及二维转移核Overhauser效应实验，分析了游离状态和半乳糖凝集素结合状态下的Galβ1-2Galβ1-R构象。通过分子动力学（MD）和随机游走分子力学（RAMM）计算，对配体的空间参数进行计算机辅助分析，考虑从ε = 1到ε = 80的不同介电常数约束以及各种力场，有助于确定自由状态的能量最小值。核磁共振衍生的残基间距离约束实现了构象映射。从半乳糖凝集素-配体复合物的转移核Overhauser效应实验中获得的两个重叠的残基间距离约束清楚地支持了这样一种观点，即结合状态下二糖的构象至少非常接近其在溶液中的全局能量最低状态。
