Unfolding of Ribonuclease A on Silica Nanoparticle Surfaces

Abstract

This paper reports on the unfolding behavior of ribonuclease A (RNase A) on silica nanoparticle surfaces and quantitively demonstrates that nanoscale size and surface curvature play key roles in influencing the stability of adsorbed proteins. Urea denaturation analyses showed that the thermodynamic stability of RNase A decreased upon adsorption onto the nanoparticles, with greater decrease on larger nanoparticles. The stability changes of RNase A correlate well with the changes in the protein-nanoparticle interactions, which increase as the surface contact area and surface charge interaction increases. This study, therefore, provides fundamental information on the effect of nanoscale surfaces on protein structure and function.

Quantum dots induce heat shock-related cytotoxicity at intracellular environment

“…The generated ROS from the QDs surface possibly induces heat shock stress. Recent research reports point to the fact that nanoparticles, other than QDs, can affect protein conformation/folding (Shang et al 2007), protein aggregation/fibrillation (Linse et al 2007;Chen et al 2012 and production of ROS (Uchino et al 2002;Li et al 2003). Hence, our observations may be taken as an indication that CdSe/ZnS QDs, themselves, can trigger similar in vitro reactions as a consequence of their size and that the HSP activity observed is the outcome of this effect.…”

Inorganic nanomaterial-based biocatalysts

“…In this study, the greater loss of α-helicity and enzyme activity was observed for the lysozyme immobilized onto 100 nm SiO2 nanoparticles comparing with 4 and 20 nm nanoparticles. Considering dimensions of lysozyme (4.5 × 3.5 × 3.5 nm), smaller nanoparticles (i.e., 4 nm SiO2 nanoparticles) perhaps promote the retention of more nativelike structure and function when compared to their larger (and hence less curved) particle counterparts (59,60). Thus, the surface curvature of nanomaterials needs to be carefully selected to be able to improve enzyme activity.…”

The on-bead digestion of protein corona on nanoparticles by trypsin immobilized on the magnetic nanoparticle

“…To characterize proteins adsorbed on the surface of nanoparticles, technologies such as the dynamic light scattering (DLS) [15,17,18], transmission electron microscopy (TEM) [18], circular dichroism (CD) [18,19], size exclusion chromatography (SEC) [20,21], isothermal titration calorimetry (ITC) [20,22], fluorescence quenching technology [23] and surface plasmon resonance (SPR) [21,22], and mass spectrometry (MS) etc. have been performed to determine the thickness, density, arrangement, conformation, affinity and identification of proteins on nanoparticles [9].…”