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Cysteine-capped gold nanoparticles suppress aggregation of proteins exposed to heat stress
Article first published online: 22 FEB 2013
Copyright © 2013 International Union of Biochemistry and Molecular Biology, Inc.
Volume 65, Issue 5, pages 454–461, May 2013
How to Cite
Luthuli, S. D., Chili, M. M., Revaprasadu, N. and Shonhai, A. (2013), Cysteine-capped gold nanoparticles suppress aggregation of proteins exposed to heat stress. IUBMB Life, 65: 454–461. doi: 10.1002/iub.1146
- Issue published online: 22 APR 2013
- Article first published online: 22 FEB 2013
- Manuscript Accepted: 9 JAN 2013
- Manuscript Received: 27 NOV 2012
- gold nanoparticles;
- malate dehydrogenase;
- bovine serum albumin;
- heat shock protein 70;
- heat-induced aggregation
Gold nanoparticles show a lot of promise as potential agents for drug delivery and disease diagnosis. Because of this, it is important that the interaction between gold nanoparticles and biomolecules be well characterized to avoid undesirable consequences. In this study, gold nanoparticles were synthesized by the reduction of gold salt by sodium borohydride in the presence of cysteine as the capping agent. The physical features of the nanoparticles were analyzed using Ultraviolet–Visible spectrophotometry and transmission electron microscopy. The interaction between gold nanoparticles and the following proteins: bovine serum albumin, citrate synthase, malate dehydrogenase, and human heat shock protein 70 was investigated by UV–Vis spectrophotometry. The stability of the proteins against heat stress was assessed by monitoring their aggregation at 48 °C, either in the presence or absence of gold nanoparticles. The gold nanoparticles were capable of suppressing the heat-induced aggregation of the proteins. Furthermore, apart from possessing independent protein-aggregation suppression function, the AuNPs also augmented the chaperone function of human heat shock protein 70. Findings from this study demonstrate that cyteine-coated gold nanoparticles exhibit chaperone-like activity and have the capability to stabilize proteins to which they may be conjugated. © 2013 IUBMB Life, 65(5):454–461, 2013.