Document Detail


Harnessing the mechanism of glutathione reductase for synthesis of active site bound metallic nanoparticles and electrical connection to electrodes.
MedLine Citation:
PMID:  18166048     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
It is demonstrated herein that the FAD-dependent enzyme glutathione reductase (GR) catalyzes the NADPH-dependent reduction of AuCl4-, forming gold nanoparticles at the active site that are tightly bound through the catalytic cysteines. The nanoparticles can be removed from the GR active site with thiol reagents such as 2-mercaptoethanol. The deep enzyme active site cavity stabilizes very small metallic clusters and prevents them from aggregating in the absence of capping ligands. The behavior of the GR-nanoparticle complexes in solution, and their electrochemical properties when immobilized on graphite paper electrodes are presented. It is shown that the borohydride ion, a known reducing agent for GR, is catalytically oxidized by larger GR-nanoparticle (>or=150 gold atoms) complexes generating catalytic currents, whereas NADPH (the natural reducing agent for GR) is not. It is proposed that the surface of the Toray graphite paper electrode employed here interferes with NADPH binding to the GR-nanoparticle complex. The catalytic currents with borohydride begin at the potential of GR-bound FAD, showing that there is essentially zero resistance to electron transfer (i.e., zero overpotential) from GR-bound FAD through the gold nanoparticle to the electrode.
Authors:
Daniel Scott; Michael Toney; Martin Muzikár
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.     Date:  2008-01-01
Journal Detail:
Title:  Journal of the American Chemical Society     Volume:  130     ISSN:  1520-5126     ISO Abbreviation:  J. Am. Chem. Soc.     Publication Date:  2008 Jan 
Date Detail:
Created Date:  2008-01-16     Completed Date:  2008-02-19     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7503056     Medline TA:  J Am Chem Soc     Country:  United States    
Other Details:
Languages:  eng     Pagination:  865-74     Citation Subset:  IM    
Affiliation:
Department of Chemistry, University of California, Davis, California 95616, USA.
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MeSH Terms
Descriptor/Qualifier:
Bacterial Proteins / chemistry*
Binding Sites
Catalysis
Electrodes
Electron Transport
Escherichia coli / enzymology
Flavin-Adenine Dinucleotide / chemistry
Glutathione Reductase / chemistry*
Gold / chemistry*
Gold Compounds / metabolism*
Hydrogen-Ion Concentration
Mercaptoethanol / chemistry
Metal Nanoparticles / chemistry*
NADP / chemistry
Oxidation-Reduction
Oxidoreductases / chemistry
Chemical
Reg. No./Substance:
0/Bacterial Proteins; 0/Gold Compounds; 11118-27-7/gold chloride; 146-14-5/Flavin-Adenine Dinucleotide; 53-59-8/NADP; 60-24-2/Mercaptoethanol; 7440-57-5/Gold; EC 1.-/Oxidoreductases; EC 1.8.1.7/Glutathione Reductase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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