Paramagnetic Nanoparticles Leave Their Mark on Nuclear Spins of Transiently Adsorbed Proteins
Paramagnetic Nanoparticles Leave Their Mark on Nuclear Spins of Transiently Adsorbed Proteins
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DOI：
10.1021/jacs.5b11582
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发表时间：
2016-01-13
影响因子：
15
通讯作者：
Assfalg, Michael
中科院分区：
文献类型：
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作者：
Zanzoni, Serena;Pedroni, Marco;Assfalg, Michael
纳米材料在生物科学中的成功应用需要深入了解它们如何与生物分子相互作用。蛋白质与纳米颗粒（NP）的瞬时结合可以通过溶液核磁共振光谱法实现，尽管存在一些限制。将顺磁性中心并入纳米粒子为探索生物纳米界面提供了新的机会。我们提出了NMR顺磁弛豫增强作为一种新的工具，以检测NP-结合表面的蛋白质具有更高的灵敏度，也扩展了适用性的NMR调查异质生物分子混合物。泛素对钆掺杂的氟化物基纳米粒子的吸附产生了残留物特异性NMR谱线增宽效应，映射到蛋白质表面上的连续区域。重要的是，在存在竞争性蛋白质-蛋白质缔合平衡的情况下观察到相同的顺磁性指纹，例示了在拥挤的生物介质中发生的可能的相互作用。使用等温滴定量热法和上转换发射测量的相互作用进行了进一步表征。数据表明，所使用的基于氟化物的NP不是生物惰性的，而是能够进行生物分子识别。
The successful application of nanomaterials in biosciences necessitates an in-depth understanding of how they interface with biomolecules. Transient associations of proteins with nanoparticles (NPs) are accessible by solution NMR spectroscopy, albeit with some limitations. The incorporation of paramagnetic centers into NPs offers new opportunities to explore bio nano interfaces. We propose NMR paramagnetic relaxation enhancement as a new tool to detect NP-binding surfaces on proteins with increased sensitivity, also extending the applicability of NMR investigations to heterogeneous biomolecular mixtures. The adsorption of ubiquitin on gadolinium-doped fluoride-based NPs produced residue-specific NMR line-broadening effects mapping to a contiguous area on the surface of the protein. Importantly, an identical paramagnetic fingerprint was observed in the presence of a competing protein protein association equilibrium, exemplifying possible interactions taking place in crowded biological media. The interaction was further characterized using isothermal titration calorimetry and upconversion emission measurements. The data indicate that the used fluoride-based NPs are not biologically inert but rather are capable of biomolecular recognition.