Understanding Protein Structure Deformation on the Surface of Gold Nanoparticles of Varying Size.
Understanding Protein Structure Deformation on the Surface of Gold Nanoparticles of Varying Size.
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DOI：
10.1021/acs.jpcc.6b08089
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发表时间：
2016-12-15
期刊：
影响因子：
--
通讯作者：
Fitzkee NC
中科院分区：
文献类型：
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作者：
Woods KE;Perera YR;Davidson MB;Wilks CA;Yadav DK;Fitzkee NC
金纳米粒子（AuNPs）由于其独特的光学性质和生物相容性而受到关注。生物分子自发地吸附到它们的表面，这一特性可能被用于药物靶向。目前，尚不清楚纳米颗粒表面的蛋白质-AuNP相互作用是否取决于纳米颗粒的大小。在这项工作中，我们研究了不同的表面曲率是否可以诱导蛋白质展开和多层结合在不同大小的柠檬酸盐包被的金纳米粒子。最近开发的NMR为基础的方法被用来确定吸附能力，和蛋白质NMR光谱进行了比较，以确定是否纳米粒子的大小影响蛋白质在表面上的相互作用。此外，透射电子显微镜（TEM）和动态光散射（DLS）证实了NMR研究。在宽范围的金纳米粒子的大小（14-86 nm），我们表明，吸附能力可以通过假设蛋白质是紧凑的，球状的纳米粒子表面上预测。此外，无论AuNP大小如何，大约一层蛋白质被吸附。我们的研究结果持有两种蛋白质的显着不同的大小，GB 3（6 kDa）和牛碳酸酐酶（BCA，29 kDa）。然而，不稳定的drkN SH 3结构域（Δ rk 0 ≤ 0.7 kDa）似乎不遵循稳定的球状蛋白所见的相同趋势。这一观察结果表明，不稳定的蛋白质在结合到AuNP表面时可以显著变形。总之，这项工作的结果可用于提高我们对蛋白质-AuNP相互作用机制的认识，以优化其在生物医学领域的应用。
Gold nanoparticles (AuNPs) have been of recent interest due to their unique optical properties and their biocompatibility. Biomolecules spontaneously adsorb to their surface, a trait that could potentially be exploited for drug targeting. Currently, it is unclear whether protein–AuNP interactions at the nanoparticle surface are dependent on nanoparticle size. In this work, we investigate whether varying surface curvature can induce protein unfolding and multilayer binding in citrate-coated AuNPs of various sizes. A recently developed NMR-based approach was utilized to determine the adsorption capacity, and protein NMR spectra were compared to determine whether nanoparticle size influences protein interactions at the surface. In addition, transmission electron microscopy (TEM) and dynamic light scattering (DLS) were employed to corroborate the NMR studies. Over a broad range of AuNP sizes (14–86 nm), we show that adsorption capacity can be predicted by assuming that proteins are compact and globular on the nanoparticle surface. Additionally, roughly one layer of proteins is adsorbed regardless of AuNP size. Our results hold for two proteins of significantly different sizes, GB3 (6 kDa) and bovine carbonic anhydrase (BCA, 29 kDa). However, the unstable drkN SH3 domain (ΔḠ0 ≈ 0, 7 kDa) does not appear to follow the same trend seen for stable, globular proteins. This observation suggests that unstable proteins can deform significantly when bound to AuNP surfaces. Taken together, the results of this work can be used to improve our knowledge of the mechanism of protein–AuNP interactions to optimize their use in the biomedical field.