Multivalent carbohydrate–protein interactions are essential for many biological processes. Convenient characterization for multivalent binding property of proteins will aid the development of molecules to manipulate these processes. We exploited the polyproline helix II (PPII) structure as molecular scaffolds to adjust the distances between glycan ligand attachment sites at 9, 18, and 27 Å on a peptide scaffold. Optimized fluorous groups were also introduced to the peptide scaffold for immobilization to the microarray surface through fluorous interaction to control the orientation of the helical scaffolds. Using lectin LecA and antibody 2G12 as model proteins, the binding preference to the 27 Å glycopeptide scaffold, matched the distance of 26 Å between its two galactose binding sites on LecA and 31 Å spacing between oligomannose binding sites on 2G12, respectively. We further demonstrate this microarray system can aid the development of inhibitors by transforming the selected surface-bound scaffold into multivalent ligands in solution. This strategy can be extended to analyze proteins that lacking structural information to speed up the design of potent and selective multivalent ligands.

中文翻译：

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控制表面上的配体间距：基于聚脯氨酸的荧光微阵列作为空间特异性分析和糖蛋白相互作用的抑制剂开发的工具

多价碳水化合物与蛋白质的相互作用对于许多生物过程至关重要。蛋白质多价结合特性的便利表征将有助于开发分子以操纵这些过程。我们利用聚脯氨酸螺旋II（PPII）结构作为分子支架，以调节肽支架上9、18和27Å处的聚糖配体连接位点之间的距离。优化的氟基团也被引入到肽支架中，以通过氟相互作用来固定到微阵列表面，以控制螺旋支架的取向。使用凝集素LecA和抗体2G12作为模型蛋白，其对27Å糖肽支架的结合偏好，分别匹配了LecA上两个半乳糖结合位点之间26Å的距离和2G12上低聚甘露糖结合位点之间31Å的距离。我们进一步证明了该微阵列系统可以通过将选择的表面结合支架转变成溶液中的多价配体来辅助抑制剂的开发。该策略可以扩展为分析缺乏结构信息的蛋白质，从而加快有效和选择性多价配体的设计。