Article

Soft interactions at nanoparticles alter protein function and conformation in a size dependent manner.

Interdisciplinary NanoscienceCenter (iNANO), Aarhus University, 7400 Herning, Denmark.
Nano Letters (impact factor: 13.2). 11/2011; 11(11):4985-91. DOI:10.1021/nl202940k pp.4985-91
Source: PubMed

ABSTRACT Weak protein-nanoparticle (NP) interactions are studied in a low binding regime as a model for the soft protein corona around nanoparticles in complex biological fluids. Noncovalent, reversible interactions between Subtilisin Carlsberg (SC) and silica NPs shows significant alteration in conformation and enzymatic activity in a NP-size dependent manner. Very weak interactions between SC and silica NPs were revealed by centrifugation-based separations and further supported by small-angle X-ray scattering, while bovine serum albumin was used as a strongly interacting reference. Secondary and tertiary structure changes of SC were studied via circular dichroism and correlated to enzymatic activity where the enzyme kinetics showed a critical role for nanoparticle size.

0 0
 · 
0 Bookmarks
 · 
69 Views
  • Source
    Article: Ultrasmall Fluorescent Silver Nanoclusters: Protein Adsorption and Its Effects on Cellular Responses
    Li Shang, René M Dörlich, Vanessa Trouillet, Michael Bruns, G Ulrich Nienhaus
    [show abstract] [hide abstract]
    ABSTRACT: Ultrasmall silver nanoclusters (AgNCs) are a novel type of fluorescent nanoprobes that have aroused a great deal of interest in recent years. In view of many promising applications in biological research, it is of great importance to explore their behavior in the complex biological environment. In this study, interactions of AgNCs with a model protein, human serum albumin (HSA), have been systematically investigated by using a variety of techniques including absorption spectroscopy, steady-state and time-resolved fluorescence, as well as circular dichroism spectroscopy. The results show that the physicochemical properties of both proteins and AgNCs undergo changes upon their interactions; however, it appears that the overall conformation of HSA remains essentially unaffected in the complex. Binding of HSA to AgNCs was assessed by measuring tryptophan fluorescence quenching of HSA by AgNCs. Furthermore, biological implications of protein adsorption were quantitatively explored by evaluating responses of HeLa cells to AgNC exposure through live-cell fluorescence microscopy and a cytotoxicity test, revealing that protein adsorption has a significant effect on the biological response to AgNC exposure.
    Nano Research 08/2012; 2012(5):531-542. · 6.97 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

Keywords

bovine serum albumin
 
circular dichroism
 
complex biological fluids
 
critical role
 
enzyme kinetics
 
interacting reference
 
low binding regime
 
nanoparticle size
 
NP-size dependent manner
 
Secondary
 
silica NPs
 
soft protein corona
 
Subtilisin Carlsberg
 
tertiary structure changes
 
Weak protein-nanoparticle