Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan.
Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan.
Colloids Surf B Biointerfaces. 2018 Feb 1;162:60-68. doi: 10.1016/j.colsurfb.2017.11.022. Epub 2017 Nov 8.
Glycan-lectin interactions are commonly observed in nature. Analytical methods, which are used to detect lectins that rely on the use of glycan ligand-modified nanoprobes as affinity probes, have been developed. Most of the existing methods are focused on the use of synthetic glycan ligands. Nevertheless, naturally available glycoproteins, such as ovalbumin in chicken egg whites, are good sources for fabricating glycan-immobilized nanoprobes. In this study, we generated functionalized gold nanoparticles (Au NPs) from a one-pot reaction by reacting chicken egg white (cew) proteins with aqueous tetrachloroaurate. The generated Au@cew NPs are mainly encapsulated by ovalbumin, in which the surface is decorated by abundant hybrid mannose and Galβ(1→4)GlcNAc-terminated glycan ligands. Thus, the generated Au@cew NPs containing hybrid mannose and Galβ(1→4)GlcNAc have the capability to selectively bind with their corresponding lectins. Lectins including concanavalin A, banana lectin, and ricin B that have binding moieties toward specific sugars were used as the model samples. Our results showed that the generated AuNPs can be used as multiplex affinity probes for these model lectins. Lectins can be selectively released from the Au@cew NP-lectin conjugates by using specific sugars, such as mannose, glucose, and β-lactose, as the releasing agents to release specific lectins from the conjugates. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) was used as the tool to characterize the released species from the nanoprobes. The limit of detection of these model lectins using the current approach was low (in nM). The feasibility of using the Au@cew NP-based affinity MALDI-MS to selectively detect specific lectins from complex samples was also demonstrated.
糖- lectin 相互作用在自然界中很常见。已经开发出了分析方法,这些方法用于检测依赖于糖配体修饰的纳米探针作为亲和探针的 lectins。现有的大多数方法都集中在使用合成糖配体上。然而,天然存在的糖蛋白,如鸡蛋白中的卵清蛋白,是制造糖固定化纳米探针的良好来源。在这项研究中,我们通过鸡蛋白(CEW)蛋白与水合四氯金酸反应,从一锅反应中生成了功能化的金纳米粒子(Au NPs)。生成的 Au@CEW NPs 主要被卵清蛋白包裹,其表面被丰富的杂交甘露糖和 Galβ(1→4)GlcNAc 末端糖配体修饰。因此,生成的含有杂交甘露糖和 Galβ(1→4)GlcNAc 的 Au@CEW NPs 具有与相应 lectins 选择性结合的能力。包括有结合特定糖的结合部位的刀豆球蛋白 A、香蕉凝集素和蓖麻毒素 B 的 lectins 被用作模型样品。我们的结果表明,生成的 AuNPs 可作为这些模型 lectins 的多重亲和探针。通过使用特定的糖(如甘露糖、葡萄糖和β-乳糖)作为释放剂,可以从 Au@CEW NP-lectin 缀合物中选择性地释放 lectins,从而将特定的 lectins 从缀合物中释放出来。基质辅助激光解吸/电离质谱(MALDI-MS)被用作从纳米探针中释放出的物质进行特征分析的工具。使用当前方法检测这些模型 lectins 的检出限很低(在 nM 范围内)。还证明了使用基于 Au@CEW NP 的亲和 MALDI-MS 从复杂样品中选择性检测特定 lectins 的可行性。