Figure 2.

Protein stability in the PSNP corona is perturbed most for smaller nanoparticles. (A) shows a typical Trp fluorescence spectrum as GdmCl is added for R2ab. The arrow indicates increasing GdmCl. Fluorescence denaturation monitored at 344 nm following baseline correction for GB3 (B) and R2ab (C). For both proteins, the stability is most perturbed in the presence of 50 nm PSNPs. Summary of ${\Delta }_{\mathit{\text{unfold}}}{G}^{°}$ for each combination of protein and nanoparticle is shown in (D). The statistical significance of the difference relative to the GB3 or R2ab in the absence of PSNPs is shown. Significance relative to the no-nanoparticle value was assessed using one-way ANOVA with Tukey’s multiple comparisons test (n.s., not significant; *, p < 0.05, ***, p < 0.001. Error bars represent the standard error of the mean of three experiments. For (B-D), colors represent no nanoparticles (orange), 50 nm PSNPs (blue), 100 nm PSNPs (red), 200 nm PSNPs (green).