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Journal of Nanomaterials
Volume 2008, Article ID 391497, 9 pages
Research Article

Nanomaterials Enhanced Gene Expression in Yeast Cells

1Department of Chemistry and Graduate Institute of Life Science, College of Sciences, Tamkang University, Tamsui 25137, Taiwan
2Department of Chemistry and Biochemistry, College of Liberal Arts and Sciences, Northern Illinois University, Dekalb, IL 60115, USA

Received 22 August 2007; Accepted 2 January 2008

Academic Editor: Jun Liu

Copyright © 2008 Su-Fang Chien et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Metal nanomaterials are shown to enhance gene expression for rice 𝛼 -galactosidase gene ( 𝛼 -Gal) in yeast cells. Au and Ag nanoparticles and their nanocomposites, silica-Au and silica-Ag, were prepared and characterized by UV-vis spectroscopy and TEM technique. The rice 𝛼 -galactosidase gene was cloned into the yeast chromosome, where the cloned cells were precultured and induced into a medium containing each of the testing nanomaterials. The nanomaterials were observed to incorporate inside the cells, and no cell death has been detected during the course of gene expression. The enzyme activity was determined by a synthetic substrate, p-nitrophenyl- 𝛼 -D-galctopyranoside, and the yellow product yield was recorded in a spectrophotometer at 400 nm. When Au and Ag nanoparticles were incorporated with the culture, a 3–5 fold enhancement in 𝛼 -galactosidase was observed for intracellular activity as well as the secreted activity into the medium. The secreted protein was analyzed to have a pure form and displayed as a single protein band in the SDS-gel electrophoresis. The effects of size and chemical nature of nanomaterials on gene expression for the rice 𝛼 -galactosidase gene in yeast cells are discussed.