skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: CO2 Reduction Catalyzed by Nitrogenase: Pathways to Formate, Carbon Monoxide, and Methane

Journal Article · · Inorganic Chemistry
 [1];  [2];  [3];  [4];  [5];  [1]
  1. Utah State Univ., Logan, UT (United States)
  2. Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)
  3. Intel Corp., Hillsboro, OR (United States)
  4. Northwestern Univ., Evanston, IL (United States)
  5. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
+ Show Author Affiliations

The reduction of N2 to NH3 by Mo-dependent nitrogenase at its active-site metal cluster FeMo-cofactor utilizes reductive elimination (re) of Fe-bound hydrides with obligatory loss of H2 to activate the enzyme for binding/reduction of N2. Earlier work showed that wild type nitrogenase and a nitrogenase having amino acid substitutions in the MoFe protein near FeMo-cofactor can catalytically reduce CO2 by 2 or 8 electrons/protons to carbon monoxide (CO) and methane (CH4) at low rates. Here, it is demonstrated that nitrogenase preferentially reduces CO2 by 2 electrons/protons to formate (HCOO–) at rates >10 times higher than rates of CO2 reduction to yield CO and CH4. Quantum mechanical (QM) calculations on the doubly-reduced FeMo-cofactor with a Fe-bound hydride and S-bound proton (E2(2H) state) favor a direct reaction of CO2 with the hydride (‘direct hydride transfer’ reaction pathway), with facile hydride transfer to CO2 yielding formate. In contrast, a significant barrier is observed for reaction of Fe-bound CO2 with the hydride (‘associative’ reaction pathway), which leads to CO and CH4. Remarkably, in the direct hydride transfer pathway, the Fe-H behaves as a hydridic hydrogen, whereas in the associative pathway it acts as a protic hydrogen. In conclusion, MoFe proteins having amino acid substitutions near FeMo-cofactor (α-70Val→Ala, α -195His→Gln) are found to significantly alter the distribution of products between formate and CO/CH4.

Research Organization:
Utah State Univ., Logan, UT (United States). Dept. of Chemistry and Biochemistry
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
SC0010687
OSTI ID:
1466794
Journal Information:
Inorganic Chemistry, Vol. 55, Issue 17; ISSN 0020-1669
Publisher:
American Chemical Society (ACS)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 33 works
Citation information provided by
Web of Science

References (49)

Unification of reaction pathway and kinetic scheme for N2 reduction catalyzed by nitrogenase journal March 2012
Reduction of short chain alkynes by a nitrogenase α-70Ala-substituted MoFe proteinBased on the presentation given at Dalton Discussion No. 4, 10–13th January 2002, Kloster Banz, Germany. Research supported by National Institutes of Health Grant R01-GM59087. journal January 2002
Directing the Reactivity of [HFe 4 N(CO) 12 ] − toward H + or CO 2 Reduction by Understanding the Electrocatalytic Mechanism journal November 2011
Mechanistic insights into hydride transfer for catalytic hydrogenation of CO 2 with cobalt complexes journal January 2014
Catalytic and Biophysical Properties of a Nitrogenase Apo-MoFe Protein Produced by a n ifB -Deletion Mutant of Azotobacter v inelandii † journal September 1998
Connecting nitrogenase intermediates with the kinetic scheme for N2 reduction by a relaxation protocol and identification of the N2 binding state journal January 2007
Density-functional exchange-energy approximation with correct asymptotic behavior journal September 1988
FeMo Cofactor of Nitrogenase:  A Density Functional Study of States M N , M OX , M R , and M I journal December 2001
Trapping H - Bound to the Nitrogenase FeMo-Cofactor Active Site during H 2 Evolution:  Characterization by ENDOR Spectroscopy journal May 2005
Mechanism of Nitrogen Fixation by Nitrogenase: The Next Stage journal January 2014
Acetylene reduction by nitrogen-fixing preparations from Clostridium pasteurianum journal October 1966
The mechanism of Klebsiella pneumoniae nitrogenase action. Pre-steady-state kinetics of an enzyme-bound intermediate in N2 reduction and of NH3 formation journal December 1984
Nitrogenase: A Draft Mechanism journal December 2012
Self‐Consistent Molecular‐Orbital Methods. IX. An Extended Gaussian‐Type Basis for Molecular‐Orbital Studies of Organic Molecules journal January 1971
COSMO: a new approach to dielectric screening in solvents with explicit expressions for the screening energy and its gradient journal January 1993
Secondary Coordination Sphere Interactions Facilitate the Insertion Step in an Iridium(III) CO 2 Reduction Catalyst journal June 2011
Revised Basis Sets for the LANL Effective Core Potentials journal June 2008
The Mechanism of Homogeneous CO 2 Reduction by Ni(cyclam): Product Selectivity, Concerted Proton–Electron Transfer and C–O Bond Cleavage journal June 2014
Fully optimized contracted Gaussian basis sets for atoms Li to Kr journal August 1992
NWChem: A comprehensive and scalable open-source solution for large scale molecular simulations journal September 2010
A Molecular Ruthenium Electrocatalyst for the Reduction of Carbon Dioxide to CO and Formate journal June 2015
Intermolecular interactions from a natural bond orbital, donor-acceptor viewpoint journal September 1988
Electron Inventory, Kinetic Assignment (E n ), Structure, and Bonding of Nitrogenase Turnover Intermediates with C 2 H 2 and CO journal November 2005
Calculation of thermodynamic hydricities and the design of hydride donors for CO2 reduction journal July 2012
Carbon monoxide dehydrogenase from Rhodospirillum rubrum journal August 1984
Quantitative Method for Colorimetric Determination of Formate in Fermentation Media journal April 1984
Effects on Substrate Reduction of Substitution of Histidine-195 by Glutamine in the α-Subunit of the MoFe Protein of Azotobacter v inelandii Nitrogenase † journal December 1998
Structure, Function, and Mechanism of the Nickel Metalloenzymes, CO Dehydrogenase, and Acetyl-CoA Synthase journal February 2014
Nitrite and Hydroxylamine as Nitrogenase Substrates: Mechanistic Implications for the Pathway of N 2 Reduction journal August 2014
Mechanistic insights into nitrogen fixation by nitrogenase enzymes journal January 2015
Role of the MoFe Protein .alpha.-Subunit Histidine-195 Residue in FeMo-cofactor Binding and Nitrogenase Catalysis journal March 1995
Nitrogenase and nitrogenase reductase associate and dissociate with each catalytic cycle. journal June 1978
Density-functional approximation for the correlation energy of the inhomogeneous electron gas journal June 1986
Homogeneous Hydrogenation of Carbon Dioxide journal March 1995
Kinetics and mechanism of carbon dioxide insertion into a metal-hydride bond. A large solvent effect and an inverse kinetic isotope effect journal July 1986
Formation of a metal-hydride bond and the insertion of carbon dioxide. Key steps in the electrocatalytic reduction of carbon dioxide to formate anion journal January 1991
Carbon dioxide reduction to methane and coupling with acetylene to form propylene catalyzed by remodeled nitrogenase journal November 2012
Selective Electrocatalytic Reduction of CO 2 to Formate by Water-Stable Iridium Dihydride Pincer Complexes journal March 2012
Carbonyl sulfide and carbon dioxide as new substrates, and carbon disulfide as a new inhibitor, of nitrogenase journal April 1995
On reversible H2 loss upon N2 binding to FeMo-cofactor of nitrogenase journal September 2013
Nitrogenase reduction of carbon-containing compounds journal August 2013
Mechanism of Molybdenum Nitrogenase journal January 1996
Bio-inspired mechanistic insights into CO2 reduction journal April 2015
Interactions among substrates and inhibitors of nitrogenase. journal January 1975
Predicting the reactivity of hydride donors in water: thermodynamic constants for hydrogen journal January 2015
Misconception of reductive elimination of H 2 , in the context of the mechanism of nitrogenase journal January 2015
Frontiers, Opportunities, and Challenges in Biochemical and Chemical Catalysis of CO 2 Fixation journal June 2013
Isolation of an iron-molybdenum cofactor from nitrogenase journal August 1977
Identification of a Key Catalytic Intermediate Demonstrates That Nitrogenase Is Activated by the Reversible Exchange of N 2 for H 2 journal March 2015

Cited By (8)

Interfacing nature's catalytic machinery with synthetic materials for semi-artificial photosynthesis. text January 2018
Carbon Dioxide Insertion into Bridging Iron Hydrides: Kinetic and Mechanistic Studies: Carbon Dioxide Insertion into Bridging Iron Hydrides: Kinetic and Mechanistic Studies journal February 2019
Computational Investigations of the Chemical Mechanism of the Enzyme Nitrogenase journal January 2020
Critical computational analysis illuminates the reductive-elimination mechanism that activates nitrogenase for N 2 reduction journal October 2018
Selective electroreduction of CO 2 to formate on 3D [100] Pb dendrites with nanometer-sized needle-like tips journal January 2017
Biofunctionalized conductive polymers enable efficient CO 2 electroreduction journal August 2017
Interfacing nature’s catalytic machinery with synthetic materials for semi-artificial photosynthesis journal October 2018
Influence of Energy and Electron Availability on In Vivo Methane and Hydrogen Production by a Variant Molybdenum Nitrogenase journal March 2019

Similar Records

CO2 Reduction Catalyzed by Nitrogenase: Pathways to Formate, Carbon Monoxide, and Methane
Journal Article · Tue Sep 06 00:00:00 EDT 2016 · Journal of the American Chemical Society · OSTI ID:1466794
+3 more
A conformational equilibrium in the nitrogenase MoFe protein with an α-V70I amino acid substitution illuminates the mechanism of H2 formation
Journal Article · Thu Jan 12 00:00:00 EST 2023 · Faraday Discussions · OSTI ID:1466794
+5 more
Reductive Elimination of H2 Activates Nitrogenase to Reduce the N≡N Triple Bond: Characterization of the E4(4H) Janus Intermediate in Wild-Type Enzyme
Journal Article · Tue Aug 16 00:00:00 EDT 2016 · Journal of the American Chemical Society · OSTI ID:1466794
+3 more

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
FeS cluster
Mechanism
Calculation
Metalloenzyme