Design and Synthesis of High-Avidity Tetravalent Glycoclusters as Probes for Sambucus sieboldiana Agglutinin and Characterization of their Binding Properties

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• 作者：Makoto Ogata ; Megumi Yano ; Seiichiro Umemura ; Takeomi Murata ; Enoch Y. Park ; Yuka Kobayashi ; Tomohiro Asai ; Naoto Oku ; Naoki Nakamura ; Ichiro Matsuo ; Taichi Usui
• 刊名：Bioconjugate Chemistry
• 出版年：2012
• 出版时间：January 18, 2012
• 年：2012
• 卷：23
• 期：1
• 页码：97-105
• 全文大小：415K
• 年卷期：v.23,no.1(January 18, 2012)
• ISSN：1520-4812

文摘

We designed and synthesized three tetravalent sialo-glycoclusters that had different separations between the terminal sialic acids and the linking carboxy groups of the ethylene glycol bis(尾-aminoethyl ether)-N,N,N鈥?/i>,N鈥?/i>-tetraacetate scaffold to serve as ligands for the sialic acid-binding lectin Sambucus sieboldiana agglutinin (SSA). The interaction between each glycocluster and SSA was characterized by hemagglutination inhibition, quantitative precipitation, and double-diffusion assays. For the precipitation assays, the precipitin curves indicated that the ligands and SSA bound in either a 1:1 or a 1:2 ratio, i.e., stoichiometrically. The strong interactions of these sialo-glycoclusters with SSA could be ascribed to a combination of multivalency and spacer effects. We also assessed the nature of the ligand鈥揝SA complexes by isothermal titration calorimetry and dynamic light scattering. The results of those experiments indicated that formation of intermolecular complexes occurred at less than stoichiometric ratios of ligand to SSA concentrations and that, as the concentrations of the ligands increased, larger cross-linked aggregates formed. Large aggregates that were present concurrently with visible precipitation and with a particle size centered at 600 to 800 nm were identified by dynamic light scattering.