Electron Paramagnetic Resonance Spectroscopy

  • Karamatullah Danyal
  • Zhi-Yong Yang
  • Lance C. SeefeldtEmail author
Part of the Methods in Molecular Biology book series (MIMB, volume 766)


EPR spectroscopy has been an important tool in nitrogenase research for the last 50 years. The three metalloclusters in nitrogenase, the Fe protein [4Fe–4S] cluster, and the MoFe protein P-cluster, and FeMo-cofactor, all have EPR spectra when poised in the appropriate paramagnetic states. EPR spectroscopy can probe changes in the electronic properties of each metal cluster, such as when substrates bind, and can provide a definitive method for observing changes in the redox states of the clusters. In this chapter, the methods for analysis of the three metal clusters of nitrogenase by EPR spectroscopy are described, along with methods for trapping substrate-derived intermediates on the active site that are amenable to characterization by EPR and other magnetic resonance spectroscopy techniques.

Key words

Nitrogenase mechanism intermediate trapping substrate electron paramagnetic resonance (EPR) electron spin resonance (ESR) 



The authors acknowledge the long collaboration with the Brian Hoffman and Dennis Dean laboratories in advancing understanding of nitrogenase. Work in the laboratory of the authors is supported by a generous grant from the National Institutes of Health (GM59087). The authors also acknowledge the help and guidance from Dr. Brian Bennett of the National Biomedical EPR Center for EPR simulations.


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Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • Karamatullah Danyal
    • 1
  • Zhi-Yong Yang
    • 1
  • Lance C. Seefeldt
    • 1
    Email author
  1. 1.Department of Chemistry and BiochemistryUtah State UniversityLoganUSA

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