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Title: X-ray Magnetic Circular Dichroism Spectroscopy Applied to Nitrogenase and Related Models: Experimental Evidence for a Spin-Coupled Molybdenum(III) Center

Abstract

Nitrogenase enzymes catalyze the reduction of atmospheric dinitrogen to ammonia utilizing a Mo-7Fe-9S-C active site, the so-called FeMoco cluster. FeMoco and an analogous small-molecule (Et4N)[(Tp)MoFe 3S 4Cl 3] cubane have both been proposed to contain unusual spin-coupled Mo-III sites with an S(Mo)=1/2 non-Hund configuration at the Mo atom. Herein, we present Fe and Mo L 3-edge X-ray magnetic circular dichroism (XMCD) spectroscopy of the (Et 4N)[(Tp)MoFe 3S 4Cl 3] cubane and Fe L 2,3-edge XMCD spectroscopy of the MoFe protein (containing both FeMoco and the 8Fe-7S P-cluster active sites). As the P-clusters of MoFe protein have an S=0 total spin, these are effectively XMCD-silent at low temperature and high magnetic field, allowing for FeMoco to be selectively probed by Fe L 2,3-edge XMCD within the intact MoFe protein. Further, Mo L 3-edge XMCD spectroscopy of the cubane model has provided experimental support for a local S(Mo)=1/2 configuration, demonstrating the power and selectivity of XMCD.

Authors:
ORCiD logo [1];  [1];  [1];  [2];  [2];  [3]; ORCiD logo [1]
  1. Max Planck Institute for Chemical Energy Conversion, Stiftstrasse (Germany). Inorganic Spectroscopy
  2. Albert Ludwigs Univ. of Freiburg (Germany). Inst. for Biochemistry and BIOSS Centre for Biological Signalling Studies
  3. Argonne National Lab. (ANL), Argonne, IL (United States)
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
European Commission - Community Research and Development Information Service (CORDIS) - Seventh Framework Programme (FP7); German Research Foundation (DFG); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1559977
Alternate Identifier(s):
OSTI ID: 1526781
Grant/Contract Number:  
AC02-06CH11357
Resource Type:
Accepted Manuscript
Journal Name:
Angewandte Chemie (International Edition)
Additional Journal Information:
Journal Name: Angewandte Chemie (International Edition); Journal Volume: 58; Journal Issue: 28; Journal ID: ISSN 1433-7851
Publisher:
Wiley
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; FeMo cofactor; X-ray magnetic circular dichroism spectroscopy; nitrogen fixation; nitrogenase; spin coupling

Citation Formats

Kowalska, Joanna K., Henthorn, Justin T., Van Stappen, Casey, Trncik, Christian, Einsle, Oliver, Keavney, David, and DeBeer, Serena. X-ray Magnetic Circular Dichroism Spectroscopy Applied to Nitrogenase and Related Models: Experimental Evidence for a Spin-Coupled Molybdenum(III) Center. United States: N. p., 2019. Web. doi:10.1002/anie.201901899.
Kowalska, Joanna K., Henthorn, Justin T., Van Stappen, Casey, Trncik, Christian, Einsle, Oliver, Keavney, David, & DeBeer, Serena. X-ray Magnetic Circular Dichroism Spectroscopy Applied to Nitrogenase and Related Models: Experimental Evidence for a Spin-Coupled Molybdenum(III) Center. United States. doi:10.1002/anie.201901899.
Kowalska, Joanna K., Henthorn, Justin T., Van Stappen, Casey, Trncik, Christian, Einsle, Oliver, Keavney, David, and DeBeer, Serena. Wed . "X-ray Magnetic Circular Dichroism Spectroscopy Applied to Nitrogenase and Related Models: Experimental Evidence for a Spin-Coupled Molybdenum(III) Center". United States. doi:10.1002/anie.201901899. https://www.osti.gov/servlets/purl/1559977.
@article{osti_1559977,
title = {X-ray Magnetic Circular Dichroism Spectroscopy Applied to Nitrogenase and Related Models: Experimental Evidence for a Spin-Coupled Molybdenum(III) Center},
author = {Kowalska, Joanna K. and Henthorn, Justin T. and Van Stappen, Casey and Trncik, Christian and Einsle, Oliver and Keavney, David and DeBeer, Serena},
abstractNote = {Nitrogenase enzymes catalyze the reduction of atmospheric dinitrogen to ammonia utilizing a Mo-7Fe-9S-C active site, the so-called FeMoco cluster. FeMoco and an analogous small-molecule (Et4N)[(Tp)MoFe3S4Cl3] cubane have both been proposed to contain unusual spin-coupled Mo-III sites with an S(Mo)=1/2 non-Hund configuration at the Mo atom. Herein, we present Fe and Mo L3-edge X-ray magnetic circular dichroism (XMCD) spectroscopy of the (Et4N)[(Tp)MoFe3S4Cl3] cubane and Fe L2,3-edge XMCD spectroscopy of the MoFe protein (containing both FeMoco and the 8Fe-7S P-cluster active sites). As the P-clusters of MoFe protein have an S=0 total spin, these are effectively XMCD-silent at low temperature and high magnetic field, allowing for FeMoco to be selectively probed by Fe L2,3-edge XMCD within the intact MoFe protein. Further, Mo L3-edge XMCD spectroscopy of the cubane model has provided experimental support for a local S(Mo)=1/2 configuration, demonstrating the power and selectivity of XMCD.},
doi = {10.1002/anie.201901899},
journal = {Angewandte Chemie (International Edition)},
number = 28,
volume = 58,
place = {United States},
year = {2019},
month = {5}
}

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Works referenced in this record:

The role of X-ray spectroscopy in understanding the geometric and electronic structure of nitrogenase
journal, June 2015

  • Kowalska, Joanna; DeBeer, Serena
  • Biochimica et Biophysica Acta (BBA) - Molecular Cell Research, Vol. 1853, Issue 6
  • DOI: 10.1016/j.bbamcr.2014.11.027

Investigation of CO bound to inhibited forms of nitrogenase MoFe protein by 13C ENDOR
journal, August 1995

  • Pollock, Robert C.; Lee, Hong-In; Cameron, Linda M.
  • Journal of the American Chemical Society, Vol. 117, Issue 33
  • DOI: 10.1021/ja00138a033

A Practical Guide to High-resolution X-ray Spectroscopic Measurements and their Applications in Bioinorganic Chemistry
journal, July 2016

  • Kowalska, Joanna K.; Lima, Frederico A.; Pollock, Christopher J.
  • Israel Journal of Chemistry, Vol. 56, Issue 9-10
  • DOI: 10.1002/ijch.201600037

Nitrogenase. VIII. Mössbauer and EPR spectroscopy. The MoFe protein component from Azotobacter vinelandii OP
journal, July 1975

  • Münck, E.; Rhodes, H.; Orme-Johnson, W. H.
  • Biochimica et Biophysica Acta (BBA) - Protein Structure, Vol. 400, Issue 1
  • DOI: 10.1016/0005-2795(75)90124-5

Electron Paramagnetic Resonance of Nitrogenase and Nitrogenase Components from Clostridium pasteurianum W5 and Azotobacter vinelandii OP
journal, November 1972

  • Orme-Johnson, W. H.; Hamilton, W. D.; Jones, T. L.
  • Proceedings of the National Academy of Sciences, Vol. 69, Issue 11
  • DOI: 10.1073/pnas.69.11.3142

Structural Basis of Biological Nitrogen Fixation
journal, January 1996

  • Howard, James B.; Rees, Douglas C.
  • Chemical Reviews, Vol. 96, Issue 7
  • DOI: 10.1021/cr9500545

Structural models for the metal centers in the nitrogenase molybdenum-iron protein
journal, September 1992


Competitive cobalt for zinc substitution in mammalian methionine sulfoxide reductase B1 overexpressed in E. coli: structural and functional insight
journal, November 2013

  • Shumilina, Elena; Dobrovolska, Olena; Del Conte, Rebecca
  • JBIC Journal of Biological Inorganic Chemistry, Vol. 19, Issue 1
  • DOI: 10.1007/s00775-013-1064-7

Mechanism of Nitrogen Fixation by Nitrogenase: The Next Stage
journal, January 2014

  • Hoffman, Brian M.; Lukoyanov, Dmitriy; Yang, Zhi-Yong
  • Chemical Reviews, Vol. 114, Issue 8
  • DOI: 10.1021/cr400641x

Natural widths of atomic K and L levels, K α X‐ray lines and several K L L Auger lines
journal, April 1979

  • Krause, M. O.; Oliver, J. H.
  • Journal of Physical and Chemical Reference Data, Vol. 8, Issue 2
  • DOI: 10.1063/1.555595

Iron-sulfur clusters in the molybdenum-iron protein component of nitrogenase. Electron paramagnetic resonance of the carbon monoxide inhibited state
journal, October 1979

  • Davis, Lawrence C.; Henzl, Michael T.; Burris, R. H.
  • Biochemistry, Vol. 18, Issue 22
  • DOI: 10.1021/bi00589a014

EXAFS studies on the PN and POX states of the P-clusters in nitrogenase
journal, August 1998

  • Musgrave, Kristin B.; Liu, Hongbin Isaac; Ma, L.
  • JBIC Journal of Biological Inorganic Chemistry, Vol. 3, Issue 4
  • DOI: 10.1007/s007750050243

Reductive Elimination of H 2 Activates Nitrogenase to Reduce the N≡N Triple Bond: Characterization of the E 4 (4H) Janus Intermediate in Wild-Type Enzyme
journal, August 2016

  • Lukoyanov, Dmitriy; Khadka, Nimesh; Yang, Zhi-Yong
  • Journal of the American Chemical Society, Vol. 138, Issue 33
  • DOI: 10.1021/jacs.6b06362

Structure−Function Relationships of Alternative Nitrogenases
journal, January 1996


New structural insights into the iron-molybdenum cofactor from Azotobacter vinelandii nitrogenase through sulfur K and molybdenum L x-ray absorption edge studies
journal, June 1988

  • Hedman, Britt.; Frank, Patrick.; Gheller, Stephen F.
  • Journal of the American Chemical Society, Vol. 110, Issue 12
  • DOI: 10.1021/ja00220a013

Comparative electronic structures of nitrogenase FeMoco and FeVco
journal, January 2017

  • Rees, Julian A.; Bjornsson, Ragnar; Kowalska, Joanna K.
  • Dalton Transactions, Vol. 46, Issue 8
  • DOI: 10.1039/C7DT00128B

Metal-Ion Valencies of the FeMo Cofactor in CO-Inhibited and Resting State Nitrogenase by 57 Fe Q-Band ENDOR
journal, November 1997

  • Lee, Hong-In; Hales, Brian J.; Hoffman, Brian M.
  • Journal of the American Chemical Society, Vol. 119, Issue 47
  • DOI: 10.1021/ja971508d

A Confirmation of the Quench-Cryoannealing Relaxation Protocol for Identifying Reduction States of Freeze-Trapped Nitrogenase Intermediates
journal, March 2014

  • Lukoyanov, Dmitriy; Yang, Zhi-Yong; Duval, Simon
  • Inorganic Chemistry, Vol. 53, Issue 7
  • DOI: 10.1021/ic500013c

P-cluster maturation on nitrogenase MoFe protein
journal, June 2007

  • Hu, Y.; Fay, A. W.; Lee, C. C.
  • Proceedings of the National Academy of Sciences, Vol. 104, Issue 25
  • DOI: 10.1073/pnas.0704297104

Characterization of Isolated Nitrogenase FeVco
journal, September 2010

  • Fay, Aaron W.; Blank, Michael A.; Lee, Chi Chung
  • Journal of the American Chemical Society, Vol. 132, Issue 36
  • DOI: 10.1021/ja1019657

The molybdenum site of nitrogenase. 2. A comparative study of molybdenum-iron proteins and the iron-molybdenum cofactor by x-ray absorption spectroscopy
journal, June 1978

  • Cramer, Stephen P.; Gillum, William O.; Hodgson, Keith O.
  • Journal of the American Chemical Society, Vol. 100, Issue 12
  • DOI: 10.1021/ja00480a027

Structural insights into a protein-bound iron-molybdenum cofactor precursor
journal, January 2006

  • Corbett, M. C.; Hu, Y.; Fay, A. W.
  • Proceedings of the National Academy of Sciences, Vol. 103, Issue 5
  • DOI: 10.1073/pnas.0507853103

Fluorescence detected soft XAS and MCD - applications to bioinorganic systems
journal, May 1996


Substrate Interactions with the Nitrogenase Active Site
journal, March 2005

  • Dos Santos, Patricia C.; Igarashi, Robert Y.; Lee, Hong-In
  • Accounts of Chemical Research, Vol. 38, Issue 3
  • DOI: 10.1021/ar040050z

The iron-molybdenum cofactor of nitrogenase
journal, December 1990


Trapping an Intermediate of Dinitrogen (N 2 ) Reduction on Nitrogenase
journal, September 2009

  • Barney, Brett M.; Lukoyanov, Dmitriy; Igarashi, Robert Y.
  • Biochemistry, Vol. 48, Issue 38
  • DOI: 10.1021/bi901092z

Detection of EPR signals assigned to the 1-equiv-oxidized P-clusters of the nitrogenase MoFe-protein from Azotobacter vinelandii
journal, October 1993

  • Tittsworth, Roland C.; Hales, Brian J.
  • Journal of the American Chemical Society, Vol. 115, Issue 21
  • DOI: 10.1021/ja00074a050

Identification of a spin-coupled Mo( iii ) in the nitrogenase iron–molybdenum cofactor
journal, January 2014

  • Bjornsson, Ragnar; Lima, Frederico A.; Spatzal, Thomas
  • Chem. Sci., Vol. 5, Issue 8
  • DOI: 10.1039/C4SC00337C

14 N Electron Spin−Echo Envelope Modulation of the S = 3 / 2 Spin System of the Azotobacter vinelandii Nitrogenase Iron−Molybdenum Cofactor
journal, September 1998

  • Lee, Hong-In; Thrasher, Kristin S.; Dean, Dennis R.
  • Biochemistry, Vol. 37, Issue 38
  • DOI: 10.1021/bi980956a

Catalysis-dependent selenium incorporation and migration in the nitrogenase active site iron-molybdenum cofactor
journal, December 2015


Exploring Electron/Proton Transfer and Conformational Changes in the Nitrogenase MoFe Protein and FeMo-cofactor Through Cryoreduction/EPR Measurements
journal, July 2016

  • Davydov, Roman; Khadka, Nimesh; Yang, Zhi-Yong
  • Israel Journal of Chemistry, Vol. 56, Issue 9-10
  • DOI: 10.1002/ijch.201600026

Evidence for Interstitial Carbon in Nitrogenase FeMo Cofactor
journal, November 2011


STRUCTURE: Nitrogenase Reveals Its Inner Secrets
journal, September 2002


The molybdenum site of nitrogenase. Preliminary structural evidence from x-ray absorption spectroscopy
journal, May 1978

  • Cramer, Stephen P.; Hodgson, Keith O.; Gillum, William O.
  • Journal of the American Chemical Society, Vol. 100, Issue 11
  • DOI: 10.1021/ja00479a023

Mechanism of Molybdenum Nitrogenase
journal, January 1996

  • Burgess, Barbara K.; Lowe, David J.
  • Chemical Reviews, Vol. 96, Issue 7
  • DOI: 10.1021/cr950055x

X-ray Emission Spectroscopy Evidences a Central Carbon in the Nitrogenase Iron-Molybdenum Cofactor
journal, November 2011


A novel S = 3/2 EPR signal associated with native Fe-proteins of nitrogenase
journal, September 1985


X-ray magnetic circular dichroism—a high energy probe of magnetic properties
journal, January 2005

  • Funk, Tobias; Deb, Aniruddha; George, Simon J.
  • Coordination Chemistry Reviews, Vol. 249, Issue 1-2
  • DOI: 10.1016/j.ccr.2004.05.017

Nitrogenase and homologs
journal, December 2014

  • Hu, Yilin; Ribbe, Markus W.
  • JBIC Journal of Biological Inorganic Chemistry, Vol. 20, Issue 2
  • DOI: 10.1007/s00775-014-1225-3

Identification of the CO-Binding Cluster in Nitrogenase MoFe Protein by ENDOR of 57 Fe Isotopomers
journal, January 1996

  • Christie, Patricia D.; Lee, Hong-In; Cameron, Linda M.
  • Journal of the American Chemical Society, Vol. 118, Issue 36
  • DOI: 10.1021/ja961289g

High-resolution molybdenum K-edge X-ray absorption spectroscopy analyzed with time-dependent density functional theory
journal, January 2013

  • Lima, Frederico A.; Bjornsson, Ragnar; Weyhermüller, Thomas
  • Physical Chemistry Chemical Physics, Vol. 15, Issue 48
  • DOI: 10.1039/c3cp53133c

Molybdenum L-Edge XAS Spectra of MoFe Nitrogenase: Molybdenum L-Edge XAS Spectra of MoFe Nitrogenase
journal, November 2014

  • Bjornsson, Ragnar; Delgado-Jaime, Mario U.; Lima, Frederico A.
  • Zeitschrift für anorganische und allgemeine Chemie, Vol. 641, Issue 1
  • DOI: 10.1002/zaac.201400446

Decoding the Nitrogenase Mechanism: The Homologue Approach
journal, March 2010

  • Hu, Yilin; Ribbe, Markus W.
  • Accounts of Chemical Research, Vol. 43, Issue 3
  • DOI: 10.1021/ar900254x

Nitrogenase FeMoco investigated by spatially resolved anomalous dispersion refinement
journal, March 2016

  • Spatzal, Thomas; Schlesier, Julia; Burger, Eva-Maria
  • Nature Communications, Vol. 7, Issue 1
  • DOI: 10.1038/ncomms10902