Related Experiment Video
Updated: May 27, 2026
![Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F55858.jpg&w=3840&q=50)
Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase
Published on: December 4, 2017
X-ray emission spectroscopy evidences a central carbon in the nitrogenase iron-molybdenum cofactor
Kyle M Lancaster1, Michael Roemelt, Patrick Ettenhuber
1Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA.
Abstract:
Nitrogenase is a complex enzyme that catalyzes the reduction of dinitrogen to ammonia. Despite insight from structural and biochemical studies, its structure and mechanism await full characterization. An iron-molybdenum cofactor (FeMoco) is thought to be the site of dinitrogen reduction, but the identity of a central atom in this cofactor remains unknown. Fe Kβ x-ray emission spectroscopy (XES) of intact nitrogenase MoFe protein, isolated FeMoco, and the FeMoco-deficient nifB protein indicates that among the candidate atoms oxygen, nitrogen, and carbon, it is carbon that best fits the XES data. The experimental XES is supported by computational efforts, which show that oxidation and spin states do not affect the assignment of the central atom to C(4-). Identification of the central atom will drive further studies on its role in catalysis.
Related Concept Videos
Emission Spectra
Atomic Emission Spectroscopy: Overview
NMR Spectroscopy Of Amines
Atomic Emission Spectroscopy: Lab
Mass Spectrum: Interpretation
Atomic Emission Spectroscopy: Instrumentation

