ISSN:
1432-072X
Keywords:
Methanogenesis from acetate
;
Methanopterin
;
Methanofuran
;
Coenzyme F420
;
Coenzyme M
;
7-Mercaptoheptanoylthreonine phosphate (=component B)
;
Methanosarcina barkeri
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Cell extracts (100,000×g) of acetate grown Methanosarcina barkeri (strain MS) catalyzed CH4 and CO2 formation from acetyl-CoA with specific activities of 50 nmol·min-1·mg protein-1. CH4 formation was found to be dependent on tetrahydromethanopterin (H4MPT) (apparent K M=4 μM), coenzyme M (H-S-CoM), and 7-mercaptoheptanoylthreonine phosphate (H-S-HTP=component B) rather than on methanofuran (MFR) and coenzyme F420 (F420). Methyl-H4MPT was identified as an intermediate. This compound accumulated when H-S-CoM and H-S-HTP were omitted from the assays. These and previous results indicate that methanogenesis from acetate proceeds via acetyl phosphate, acetyl-CoA, methyl-H4MPT, and CH3-S-CoM as intermediates. The disproportionation of formaldehyde to CO2 and CH4 was also studied. This reaction was shown to be dependent on H4MPT, MFR, F420, H-S-CoM, and H-S-HTP.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00416607
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