Nickel tetrapyrrole cofactor F430: comparison of the forms bound to methyl S-coenzyme M reductase and protein free in cells of Methanobacterium thermoautotrophicum .DELTA.H

Biochemistry ◽  
1984 ◽  
Vol 23 (5) ◽  
pp. 801-804 ◽  
Author(s):  
Robert P. Hausinger ◽  
William H. Orme-Johnson ◽  
Christopher Walsh
Keyword(s):  
Methanobacterium Thermoautotrophicum ◽  
Coenzyme M ◽  
Cofactor F430 ◽  
In Cells

scholarly journals The magnetic properties of the nickel cofactor F430 in the enzyme methyl-coenzyme M reductase of Methanobacterium thermoautotrophicum

1989 ◽  
Vol 260 (2) ◽  
pp. 613-616 ◽  
Author(s):  
M R Cheesman ◽  
D Ankel-Fuchs ◽  
R K Thauer ◽  
A J Thompson
Keyword(s):  
Magnetic Circular Dichroism ◽  
Methanobacterium Thermoautotrophicum ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Coenzyme M ◽  
Equal Zero ◽  
Magnetic Circular Dichroism Spectroscopy ◽  
Oxygen Ligand ◽  
Methyl Coenzyme M Reductase ◽  
Cofactor F430

Cofactor 430 of methyl-coenzyme M reductase from Methanobacterium thermoautotrophicum was studied in both the extracted form in aqueous solution and protein-bound by using low-temperature magnetic-circular-dichroism spectroscopy. In both forms the nickel was present as high-spin paramagnetic nickel(II), spin S = 1, subject to almost equal zero-field splitting (cofactor F430, D = +9.0 cm-1, E/D = 0; methyl-coenzyme M reductase, D = +8.5 cm-1, [E/D[ = 0.2). This suggests identical axial co-ordination by oxygen ligand(s) both in aqueous cofactor F430 and in the investigated state of the protein.

scholarly journals Methane production by the membranous fraction of Methanobacterium thermoautotrophicum

1980 ◽  
Vol 190 (1) ◽  
pp. 177-182 ◽  
Author(s):  
F D Sauer ◽  
J D Erfle ◽  
S Mahadevan
Keyword(s):  
Methane Production ◽  
High Speed ◽  
High Pressures ◽  
Reductase Activity ◽  
Membrane Vesicles ◽  
Methanobacterium Thermoautotrophicum ◽  
Cell Extract ◽  
Supernatant Fraction ◽  
Coenzyme M ◽  
Intact Membrane

Intact membrane vesicles are required to synthesize methane from CO2 and H2 by disrupted preparations of Methanobacterium thermoautotrophicum cells. When membrane vesicles were removed by high-speed centrifugation at 226 600 g, the remaining supernatant fraction no longer synthesized methane. Alternatively, if vesicle structure was disrupted by passage through a Ribi cell fractionator at very high pressures (345 MPa), the bacterial cell extract, with all the particulate fraction in it, did not synthesize methane. Methyl-coenzyme M, a new coenzyme first described by McBride & Wolfe [(1971) Biochemistry 10, 2317–2324], was shown to stimulate methane production from CO2 and H2, as previously reported, but the methyl group of the coenzyme did not appear to be a precursor of methane in this reaction. No methyl-coenzyme M reductase activity was detected in the cytoplasmic fraction of M. thermoautotrophicum cells.

scholarly journals Two genetically distinct methyl-coenzyme M reductases in Methanobacterium thermoautotrophicum strain Marburg and DeltaH

1990 ◽  
Vol 194 (3) ◽  
pp. 871-877 ◽  
Author(s):  
Sabine ROSPERT ◽  
Dietmar LINDER ◽  
Joachim ELLERMANN ◽  
Rudolf K. THAUER
Keyword(s):  
Methanobacterium Thermoautotrophicum ◽  
Coenzyme M

scholarly journals Properties of the two isoenzymes of methyl-coenzyme M reductase in Methanobacterium thermoautotrophicum

1993 ◽  
Vol 217 (2) ◽  
pp. 587-595 ◽  
Author(s):  
Lutz G. BONACKER ◽  
Siegfried BAUDNER ◽  
Erhard MORSCHEL ◽  
Reinhard BOCHER ◽  
Rudolf K. THAUER
Keyword(s):  
Methanobacterium Thermoautotrophicum ◽  
Coenzyme M ◽  
Methyl Coenzyme M Reductase

Coupling of methyl coenzyme M reduction with carbon dioxide activation in extracts of Methanobacterium thermoautotrophicum

1982 ◽  
Vol 152 (2) ◽  
pp. 840-847
Author(s):  
J A Romesser ◽  
R S Wolfe
Keyword(s):  
Carbon Dioxide ◽  
Co2 Reduction ◽  
Methanobacterium Thermoautotrophicum ◽  
Coenzyme M ◽  
Cell Extracts ◽  
Low Concentrations ◽  
Efficient Reduction ◽  
High Concentrations ◽  
Reduction Of Co2 ◽  
Stimulation Of

The stimulation of carbon dioxide reduction to methane by addition of 2-(methylthio)ethanesulfonate (CH3-S-CoM) to cell extracts of Methanobacterium thermoautotrophicum was investigated. Similar stimulation of CO2 reduction by CH3-S-CoM was found for cell extracts of Methanobacterium bryantii and Methanospirillum hungatei. The CH3-S-CoM requirement could be met by the methanogenic precursors formaldehyde, serine, or pyruvate, or by 2-(ethylthio)ethanesulfonate (CH3CH2-S-CoM), but not by other coenzyme M derivatives. Efficient reduction of CO2 to CH4 was favored by low concentrations of CH3-S-CoM and high concentrations of CO2. Sulfhydryl compounds were identified as effective inhibitors of CO2 reduction. Both an allosteric model and a free-radical model for the mechanism of CO2 activation and reduction are discussed.

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