A New Mechanism for Methane Production from Methyl-Coenzyme M Reductase As Derived from Density Functional Calculations

2008 ◽  
Vol 112 (8) ◽  
pp. 2466-2482 ◽  
Author(s):  
Evert C. Duin ◽  
Michael L. McKee
Keyword(s):  
Methane Production ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Coenzyme M ◽  
Methyl Coenzyme M Reductase

Comparison of chemical properties of iron, cobalt, and nickel porphyrins, corrins, and hydrocorphins

2005 ◽  
Vol 09 (08) ◽  
pp. 581-606 ◽  
Author(s):  
Kasper P. Jensen ◽  
Ulf Ryde
Keyword(s):  
Density Functional ◽  
Hydrolysis Product ◽  
Chemical Properties ◽  
Coenzyme M ◽  
Ring Systems ◽  
Reduction Potentials ◽  
Higher Spin ◽  
Coenzyme F430 ◽  
Coenzyme B ◽  
Methyl Coenzyme M Reductase

Density functional calculations have been used to compare the geometric, electronic, and functional properties of the three important tetrapyrrole systems in biology, heme, coenzyme B 12, and coenzyme F430, formed from iron porphyrin ( Por ), cobalt corrin ( Cor ), and nickel hydrocorphin ( Hcor ). The results show that the flexibility of the ring systems follows the trend Hcor > Cor > Por and that the size of the central cavity follows the trend Cor < Por < Hcor . Therefore, low-spin Co I, Co II, and Co III fit well into the Cor ring, whereas Por seems to be more ideal for the higher spin states of iron, and the cavity in Hcor is tailored for the larger Ni ion, especially in the high-spin Ni II state. This is confirmed by the thermodynamic stabilities of the various combinations of metals and ring systems. Reduction potentials indicate that the +I and +III states are less stable for Ni than for the other metal ions. Moreover, Ni – C bonds are appreciably less stable than Co - C bonds. However, it is still possible that a Ni – CH 3 bond is formed in F 430 by a heterolytic methyl transfer reaction, provided that the donor is appropriate, e.g. if coenzyme M is protonated. This can be facilitated by the adjacent SO 3− group in this coenzyme and by the axial glutamine ligand, which stabilizes the Ni III state. Our results also show that a Ni III– CH 3 complex is readily hydrolysed to form a methane molecule and that the Ni III hydrolysis product can oxidize coenzyme B and M to a heterodisulphide in the reaction mechanism of methyl coenzyme M reductase.

scholarly journals Assembly of Methyl Coenzyme M Reductase in the Methanogenic ArchaeonMethanococcus maripaludis

2018 ◽  
Vol 200 (7) ◽  
Author(s):  
Zhe Lyu ◽  
Chau-Wen Chou ◽  
Hao Shi ◽  
Liangliang Wang ◽  
Robel Ghebreab ◽  
...  
Keyword(s):  
Heterologous Expression ◽  
Methane Production ◽  
Active Sites ◽  
Net Primary Production ◽  
Expression System ◽  
Anaerobic Oxidation Of Methane ◽  
Coenzyme M ◽  
Heterologous Expression System ◽  
Content Type ◽  
Methyl Coenzyme M Reductase

ABSTRACTMethyl coenzyme M reductase (MCR) is a complex enzyme that catalyzes the final step in biological methanogenesis. To better understand its assembly, the recombinant MCR from the thermophileMethanothermococcus okinawensis(rMCRok) was expressed in the mesophileMethanococcus maripaludis. The rMCRokwas posttranslationally modified correctly and contained McrD and the unique nickel tetrapyrrole coenzyme F430. Subunits of the nativeM. maripaludis(MCRmar) were largely absent, suggesting that the recombinant enzyme was formed by an assembly of cotranscribed subunits. Strong support for this hypothesis was obtained by expressing a chimeric operon comprising the His-taggedmcrAfromM. maripaludisand themcrBDCGfromM. okinawensisinM. maripaludis. The His-tagged purified rMCR then contained theM. maripaludisMcrA and theM. okinawensisMcrBDG. The present study prompted us to form a working model for MCR assembly, which can be further tested by the heterologous expression system established here.IMPORTANCEApproximately 1.6% of the net primary production of plants, algae, and cyanobacteria are processed by biological methane production in anoxic environments. This accounts for about 74% of the total global methane production, up to 25% of which is consumed by anaerobic oxidation of methane (AOM). Methyl coenzyme M reductase (MCR) is the key enzyme in both methanogenesis and AOM. MCR is assembled as a dimer of two heterotrimers, where posttranslational modifications and F430cofactors are embedded in the active sites. However, this complex assembly process remains unknown. Here, we established a heterologous expression system for MCR to learn how MCR is assembled.

scholarly journals Methyl-coenzyme M reductase A as an indicator to estimate methane production from dairy cows

2015 ◽  
Vol 98 (6) ◽  
pp. 4074-4083 ◽  
Author(s):  
M.A. Aguinaga Casañas ◽  
N. Rangkasenee ◽  
N. Krattenmacher ◽  
G. Thaller ◽  
C.C. Metges ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Methane Production ◽  
Coenzyme M ◽  
Methyl Coenzyme M Reductase

Density Functional Calculations of EPR Parameter g Tensors of Some Transition Metal Complexes

2011 ◽  
Vol 2 (2) ◽  
pp. 139-141
Author(s):  
Vinita Prajapati ◽  
◽  
P.L.Verma P.L.Verma ◽  
Dhirendra Prajapati ◽  
B.K.Gupta B.K.Gupta
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Density Functional Calculations ◽  
Density Functional

scholarly journals High-throughput density functional calculations to optimize properties and interfacial chemistry of piezoelectric materials

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Jordan A. Barr ◽  
Fang-Yin Lin ◽  
Michael Ashton ◽  
Richard G. Hennig ◽  
Susan B. Sinnott
Keyword(s):  
High Throughput ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Piezoelectric Materials ◽  
Interfacial Chemistry

scholarly journals On the Effects of Doping on the Catalytic Performance of (La,Sr)CoO3. A DFT Study of CO Oxidation

Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 312 ◽  
Author(s):  
Antonella Glisenti ◽  
Andrea Vittadini
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Formation Energy ◽  
Oxygen Vacancies ◽  
Catalytic Performance ◽  
Energy Profiles ◽  
High Concentrations ◽  
3D Impurities

The effects of modifying the composition of LaCoO3 on the catalytic activity are predicted by density functional calculations. Partially replacing La by Sr ions has benefical effects, causing a lowering of the formation energy of O vacancies. In contrast to that, doping at the Co site is less effective, as only 3d impurities heavier than Co are able to stabilize vacancies at high concentrations. The comparison of the energy profiles for CO oxidation of undoped and of Ni-, Cu-m and Zn-doped (La,Sr)CoO3(100) surface shows that Cu is most effective. However, the effects are less spectacular than in the SrTiO3 case, due to the different energetics for the formation of oxygen vacancies in the two hosts.

Matrix isolation IR detection of Fex(NO)y (x,y = 1,2) complexes. Density functional calculations on FeNO and CuNO

1995 ◽  
Vol 372 (2-3) ◽  
pp. 113-125 ◽  
Author(s):  
David W. Ball ◽  
Joseph A. Chiarelli
Keyword(s):  
Density Functional Calculations ◽  
Density Functional ◽  
Matrix Isolation ◽  
Ir Detection
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