Centre for Blood Research and Department of Pathology & Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
Anal Chem. 2013 Aug 20;85(16):7786-93. doi: 10.1021/ac401306b. Epub 2013 Aug 9.
We performed quantitative analysis of the binding kinetics and affinity of carbohydrate-lectin binding and correlated them directly with the molecular and structural features of ligands presented at the nanoscale within the glycocalyx mimicking layers on surfaces. The surface plasmon resonance analysis identified that the mode of binding changed from multivalent to monovalent, which resulted in a near 1000-fold change in the equilibrium association constant, by varying the spatial distribution of carbohydrate ligands within the surface-grafted polymer layer. We identified, for the first time, that the manner in which the ligands presented on the surface has great influence on the binding at the first stage of bivalent chelating, not on the binding at the second stage. The rupture forces measured by atomic force microscope force spectroscopy also indicated that the mode of binding between lectin and ligands changed from multiple to single with variation in the ligand presentation. The dependence of lectin binding on the glycopolymer composition and grafting density is directly correlated with the nanoscale presentation of ligands on a surface, which is a determining factor in controlling the clustering and statistical effects contributing to the enhanced binding.
我们对碳水化合物-凝集素结合的结合动力学和亲和力进行了定量分析，并将其与纳米尺度内糖萼模拟层表面上呈现的配体的分子和结构特征直接相关联。表面等离子体共振分析表明，通过改变表面接枝聚合物层中碳水化合物配体的空间分布，结合模式从多价变为单价，导致平衡缔合常数发生近 1000 倍的变化。我们首次发现，配体在表面上的呈现方式对二价螯合的第一阶段结合有很大影响，而不是对第二阶段结合有影响。原子力显微镜力谱测量的断裂力也表明，随着配体呈现方式的变化，凝集素与配体之间的结合模式从多变为单。凝集素结合对糖聚合物组成和接枝密度的依赖性与表面上配体的纳米级呈现直接相关，这是控制聚类和统计效应的决定因素，这些效应有助于增强结合。
