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Electrochemical Detection of Deuterium Kinetic Isotope Effect on Extracellular Electron Transport in Shewanella oneidensis MR-1
Published on: April 16, 2018
Mixed valent sites in biological electron transfer
Edward I Solomon1, Xiangjin Xie, Abhishek Dey
1Department of Chemistry, Stanford University, Stanford, California 94305, USA. edward.solomon@stanford.edu
Chemical Society Reviews
|March 26, 2008
Summary
Biological electron transfer sites often contain multiple metals and exhibit mixed valency. This review examines metal-site delocalization using spectroscopy, crucial for understanding biological electron transfer mechanisms.
Area of Science:
- Bioinorganic Chemistry
- Biophysics
- Spectroscopy
Background:
- Many biological electron transfer (ET) active sites feature multiple metal centers.
- These sites can exist in mixed-valent states, where electrons are delocalized.
- Examples include copper-A centers and polynuclear iron-sulfur clusters.
Purpose of the Study:
- To evaluate the contributions of intra-site delocalization in biological ET.
- To explore the role of mixed-valency in electron transfer processes.
- To provide a tutorial review on assessing delocalization in metalloenzymes.
Main Methods:
- Utilized S K-edge X-ray absorption spectroscopy.
- Employed magnetic circular dichroism (MCD) spectroscopy.
- Incorporated other relevant spectroscopic techniques to probe electronic structure.
Main Results:
- Quantified the extent of electron delocalization within active sites.
- Demonstrated the spectroscopic signatures of mixed-valent metal centers.
- Correlated delocalization with electron transfer efficiency.
Conclusions:
- Intra-site delocalization plays a significant role in biological electron transfer.
- Spectroscopic methods are powerful tools for characterizing mixed-valent states.
- Understanding delocalization is key to elucidating ET mechanisms in metalloproteins.
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