Rutherford T J, Homans S W
Department of Biochemistry, University of Dundee, U.K.
Biochemistry. 1994 Aug 16;33(32):9606-14. doi: 10.1021/bi00198a029.
We have examined the dynamic behavior in solution of the biantennary glycan GlcNAc beta 1-2Man alpha 1-6(GlcNAc beta 1-2Man alpha 1-3)Man beta 1- 4GlcNAc beta 1-4GlcNAc, and its "bisected" analogue GlcNAc beta 1-2Man alpha 1-6(GlcNAc beta 1-2Man alpha 1-3)(GlcNAc beta 1- 4)Man beta 1-4GlcNAc beta 1-4GlcNAc, by use of both free dynamics simulations and restrained dynamics simulations using distance restraints derived from 1H NMR rotating frame Overhauser effect measurements. Data resulting from each type of simulation are compared with experimental data and are critically evaluated. Both methods suggest that most glycosidic linkages exhibit significant torsional oscillations in solution, and the dynamic behavior of certain linkages, notably Man alpha 1-6Man and Man alpha 1-3Man, were found to be restricted by the presence of the bisecting GlcNAc residue. The average structures so obtained were found to agree closely with those predicted in previous investigations where torsional oscillations about glycosidic linkages were not considered. In particular, the characteristic chemical shift perturbations induced by the bisecting GlcNAc residue could be explained in terms of the dynamic differences between the two glycans.
我们通过使用自由动力学模拟和使用源自¹H NMR旋转框架Overhauser效应测量的距离约束的受限动力学模拟，研究了双天线聚糖GlcNAcβ1-2Manα1-6(GlcNAcβ1-2Manα1-3)Manβ1-4GlcNAcβ1-4GlcNAc及其“平分”类似物GlcNAcβ1-2Manα1-6(GlcNAcβ1-2Manα1-3)(GlcNAcβ1-4)Manβ1-4GlcNAcβ1-4GlcNAc在溶液中的动态行为。将每种模拟类型产生的数据与实验数据进行比较并进行严格评估。两种方法均表明，大多数糖苷键在溶液中表现出明显的扭转振荡，并且发现某些键的动态行为，特别是Manα1-6Man和Manα1-3Man，受到平分的GlcNAc残基的存在的限制。发现如此获得的平均结构与先前研究中预测的结构非常吻合，在先前的研究中未考虑糖苷键的扭转振荡。特别是，平分的GlcNAc残基引起的特征性化学位移扰动可以根据两种聚糖之间的动态差异来解释。
