Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
Interfaculty Institute of Bioengineering, EPFL, CH-1015 Lausanne, Switzerland.
Nat Commun. 2016 Oct 20;7:13121. doi: 10.1038/ncomms13121.
Nanomedicine requires in-depth knowledge of nanoparticle-protein interactions. These interactions are studied with methods limited to large or fluorescently labelled nanoparticles as they rely on scattering or fluorescence-correlation signals. Here, we have developed a method based on analytical ultracentrifugation (AUC) as an absorbance-based, label-free tool to determine dissociation constants (K), stoichiometry (N), and Hill coefficient (n), for the association of bovine serum albumin (BSA) with gold nanoparticles. Absorption at 520 nm in AUC renders the measurements insensitive to unbound and aggregated proteins. Measurements remain accurate and do not become more challenging for small (sub-10 nm) nanoparticles. In AUC, frictional ratio analysis allows for the qualitative assessment of the shape of the analyte. Data suggests that small-nanoparticles/protein complexes significantly deviate from a spherical shape even at maximum coverage. We believe that this method could become one of the established approaches for the characterization of the interaction of (small) nanoparticles with proteins.
纳米医学需要深入了解纳米粒子-蛋白质相互作用。这些相互作用的研究方法仅限于大尺寸或荧光标记的纳米粒子，因为它们依赖于散射或荧光相关信号。在这里，我们开发了一种基于分析超速离心（AUC）的方法，作为一种基于吸收的、无标记的工具，用于确定牛血清白蛋白（BSA）与金纳米粒子结合的离解常数（K）、化学计量（N）和希尔系数（n）。在 AUC 中，520nm 处的吸收使测量对未结合和聚集的蛋白质不敏感。对于小（亚 10nm）纳米粒子，测量仍然准确，并且不会变得更具挑战性。在 AUC 中，摩擦比分析允许对分析物的形状进行定性评估。数据表明，即使在最大覆盖率下，小纳米粒子/蛋白质复合物也明显偏离球形。我们相信，这种方法可能成为（小）纳米粒子与蛋白质相互作用的特征描述的既定方法之一。
