PDF(Pubmed)
Abstract：
The interaction of heparin with antithrombin (AT) involves a specific sequence corresponding to the pentasaccharide GlcNAc/NS6S-GlcA-GlcNS3S6S-IdoA2S-GlcNS6S (AGA*IA). Recent studies have revealed that two AGA*IA-containing hexasaccharides, which differ in the sulfation degree of the iduronic acid unit, exhibit similar binding to AT, albeit with different affinities. However, the lack of experimental data concerning the molecular contacts between these ligands and the amino acids within the protein-binding site prevents a detailed description of the complexes. Differential epitope mapping (DEEP)-STD NMR, in combination with MD simulations, enables the experimental observation and comparison of two heparin pentasaccharides interacting with AT, revealing slightly different bound orientations and distinct affinities of both glycans for AT. We demonstrate the effectiveness of the differential solvent DEEP-STD NMR approach in determining the presence of polar residues in the recognition sites of glycosaminoglycan-binding proteins.
摘要：
肝素与抗凝血酶(AT)的相互作用涉及对应于五糖GlcNAc/NS6S-GlcA-GlcNS3S6S-IdoA2S-GlcNS6S(AGA*IA)的特定序列。最近的研究表明，两种含AGA*IA的六糖，艾杜糖醛酸单元的硫酸化程度不同，表现出与AT相似的结合，尽管有不同的亲和力。然而,缺乏有关这些配体与蛋白质结合位点内的氨基酸之间的分子接触的实验数据，无法对复合物进行详细描述。差异表位作图（DEEP）-STDNMR，结合MD模拟，能够进行两种肝素五糖与AT相互作用的实验观察和比较，揭示了两种聚糖对AT的略微不同的结合取向和不同的亲和力。我们证明了差异溶剂DEEP-STDNMR方法在确定糖胺聚糖结合蛋白识别位点中极性残基存在的有效性。
