Effects of Surface Compositional and Structural Heterogeneity on Nanoparticle–Protein Interactions: Different Protein Configurations

Abstract

As nanoparticles (NPs) enter into biological systems, they are immediately exposed to a variety and concentration of proteins. The physicochemical interactions between proteins and NPs are influenced by the surface properties of the NPs. To identify the effects of NP surface heterogeneity, the interactions between bovine serum albumin (BSA) and gold NPs (AuNPs) with similar chemical composition but different surface structures were investigated. Different interaction modes and BSA conformations were studied by dynamic light scattering, circular dichroism spectroscopy, fluorescence quenching and isothermal titration calorimetry (ITC). Depending on the surface structure of AuNPs, BSA seems to adopt either a "side-on" or an "end-on" conformation on AuNPs. ITC demonstrated that the adsorption of BSA onto AuNPs with randomly distributed polar and nonpolar groups was primarily driven by electrostatic interaction, and all BSA were adsorbed in the same process. The adsorption of BSA onto AuNPs covered with alternating domains of polar and nonpolar groups was a combination of different interactions. Overall, the results of this study point to the potential for utilizing nanoscale manipulation of NP surfaces to control the resulting NP-protein interactions.

Antibacterial activity of silver nanoparticles: A surface science insight

“…This leads to the formation of a protein corona; a layer of adsorbed macromolecules at the surface of nanoparticles [142,143]. This layer is of complex [144] and dynamic nature [145,146], and depends of the composition of the medium as well as the surface properties of the nanoparticles [147][148][149][150]. By modifying the surface of nanoparticles, the corona shell can change the interactions they have with cells as well as physical and chemical properties of the systems [146,[151][152][153].…”

Dissociation coefficients of protein adsorption to nanoparticles as quantitative metrics for description of the protein corona: A comparison of experimental techniques and methodological relevance

“…in the case fluorescence of the proteins and the NPs is quenched the NPs and the proteins are the quenchers, respectively) nonequilibrium quenching this can be described by the Stern-Volmer equation [61,62]. In this approach the quenching efficiency depends on the degree of shielding of the fluorophores by the quenchers, and thus reveals the relative accessibility of quenchers to the fluorophores, which is done by a diffusion model [60,63,64]. The Stern-Volmer constant K SV can be considered to be reciprocal to the dissociation constant K D ≈ 1/K SV , though actually K D refers to equilibrium and 1/K SV to nonequilibrium conditions.…”

Plasmonic nanoparticles and their characterization in physiological fluids

“…With isothermal titration calorimetry Huang et al [92] were able to study the interaction between NPs and adsorbed proteins. The same group also used circular dichroism spectroscopy (CD) to analyze the structure of BSA adsorbed to the surface of Au NPs.…”