Interferences of Silica Nanoparticles in Green Fluorescent Protein Folding Processes

Géraldine Klein (1, 2) , Stephanie Devineau (2) , Jean-Christophe Aude (1) , Yves Boulard (3) , Hélène Pasquier (4) , Jean Labarre (1) , Serge Pin (2) , Jean Philippe Renault (2)

1 SBIGeM - Service de Biologie Intégrative et Génétique Moléculaire
2 LIONS - Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire
3 I2BC - Institut de Biologie Intégrative de la Cellule
4 LCPO - Laboratoire de Chimie Physique D'Orsay

We investigated the relationship between unfolded proteins, silica nanoparticles and chaperonin to determine whether unfolded proteins could stick to silica surfaces and how this process could impair heat shock protein activity. The HSP60 catalyzed green fluorescent protein (GFP) folding was used as a model system. The adsorption isotherms and adsorption kinetics of denatured GFP were measured, showing that denaturation increases GFP affinity for silica surfaces. This affinity is maintained even if the surfaces are covered by a protein corona and allows silica NPs to interfere directly with GFP folding by trapping it in its unstructured state. We determined also the adsorption isotherms of HSP60 and its chaperonin activity once adsorbed, showing that SiO2 NP can interfere also indirectly with protein folding through chaperonin trapping and inhibition. This inhibition is specifically efficient when NPs are covered first with a layer of unfolded proteins. These results highlight for the first time the antichaperonin activity of silica NPs and ask new questions about the toxicity of such misfolded proteins/nanoparticles assembly towards cells.

Domains: Chemical Sciences; Material chemistry

Géraldine Klein, Stephanie Devineau, Jean-Christophe Aude, Yves Boulard, Hélène Pasquier, et al.. Interferences of Silica Nanoparticles in Green Fluorescent Protein Folding Processes. Langmuir, 2015, in press, ⟨10.1021/acs.langmuir.5b03890⟩. ⟨cea-01252408⟩