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Binding kinetics of ultrasmall gold nanoparticles with proteins


Synthetic ultrasmall nanoparticles (NPs) can be designed to interact with biologically active proteins in a controlled manner. However, rational design of NPs requires a clear understanding of their interactions with proteins and the precise molecular mechanisms that leads to association/dissociation in biological media. Although much effort has been devoted to the study of the kinetics mechanism of the protein corona formation on large NPs, the nature of NP-protein interactions in the ultrasmall regime is radically different and poorly understood. Using a combination of experimental and computational approaches, we study the interactions of a model protein, CrataBL, with ultrasmall gold NPs passivated with p-mercaptobenzoic acid (AuMBA) and glutathione (AuGSH). We have identified this system as an ideal in vitro platform to understand the dependence of binding affinity and kinetics on NP surface chemistry. We find that the structural and chemical complexity of the passivating NP layer leads to quite different association kinetics, from slow and reaction-limited (AuGSH) to fast and diffusion-limited (AuMBA). We also find that the otherwise weak and slow AuGSH-protein interactions measured in buffer are enhanced in macromolecular crowded solutions. These findings advance our mechanistic understanding of biomimetic NP-protein interactions in the ultrasmall regime, and have implications for the design and use of NPs in the crowded conditions common to all biological media.

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Publication details

The article was received on 12 Sep 2017, accepted on 08 Jan 2018 and first published on 08 Jan 2018

Article type: Paper
DOI: 10.1039/C7NR06810G
Citation: Nanoscale, 2018, Accepted Manuscript
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    Binding kinetics of ultrasmall gold nanoparticles with proteins

    A. Lira, R. Ferreira, R. Torquato, H. Zhao, M. L. Oliva, S. A. Hassan, P. Schuck and A. A. Sousa, Nanoscale, 2018, Accepted Manuscript , DOI: 10.1039/C7NR06810G

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