Coenzyme F430 as a possible catalyst for the reductive dehalogenation of chlorinated C1 hydrocarbons in methanogenic bacteria

Biochemistry ◽  
1989 ◽  
Vol 28 (26) ◽  
pp. 10061-10065 ◽  
Author(s):  
Ute E. Krone ◽  
Kerstin Laufer ◽  
Rudolf K. Thauer ◽  
Harry P. C. Hogenkamp
Keyword(s):  
Methanogenic Bacteria ◽  
Reductive Dehalogenation ◽  
Coenzyme F430

Reductive Dehalogenation of Environmental Contaminants: A Critical Review

1989 ◽  
Vol 24 (2) ◽  
pp. 299-322 ◽  
Author(s):  
R. M. Baxter
Keyword(s):  
Hydrogen Atom ◽  
Aromatic Compounds ◽  
Reductive Dechlorination ◽  
Halogen Atom ◽  
Environmental Contaminants ◽  
Methanogenic Bacteria ◽  
Photochemical Reactions ◽  
Reductive Dehalogenation ◽  
Iron Porphyrins ◽  
Aliphatic Compounds

Abstract It is generally recognized that reductive processes are more important than oxidative ones in transforming, degrading and mineralizing many environmental contaminants. One process of particular importance is reductive dehalogenation, i.e., the replacement of a halogen atom (most commonly a chlorine atom) by a hydrogen atom. A number of different mechanisms are involved in these reactions. Photochemical reactions probably play a role in some instances. Aliphatic compounds such as chloroethanes, partly aliphatic compounds such as DDT, and alicyclic compounds such as hexachlorocyclohexane are readily dechlorinated in the laboratory by reaction with reduced iron porphyrins such as hematin. Many of these are also dechlorinated by cultures of certain microorganisms, probably by the same mechanism. Such compounds, with a few exceptions, have been found to undergo reductive dechlorination in the environment. Aromatic compounds such as halobenzenes, halophenols and halobenzoic acids appear not to react with reduced iron porphyrins. Some of these however undergo reductive dechlorination both in the environment and in the laboratory. The reaction is generally associated with methanogenic bacteria. There is evidence for the existence of a number of different dechlorinating enzymes specific for different isomers. Recently it has been found that many components of polychlorinated biphenyls (PCBs), long considered to be virtually totally resistant to environmental degradation, may be reductively dechlorinated both in the laboratory and in nature. These findings suggest that many environmental contaminants may prove to be less persistent than was previously feared.

Coenzyme F430 from Methanogenic Bacteria: Complete Assignment of Configuration Based on an X-Ray Analysis of 12,13-Diepi-F430 Pentamethyl Ester and on NMR Spectroscopy

1991 ◽  
Vol 74 (4) ◽  
pp. 697-716 ◽  
Author(s):  
Gerald Färber ◽  
Walter Keller ◽  
Christoph Kratky ◽  
Berhard Jaun ◽  
Andreas Pfaltz ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Methanogenic Bacteria ◽  
X Ray ◽  
Complete Assignment ◽  
Coenzyme F430

scholarly journals An extended-X-ray-absorption-fine-structure (e.x.a.f.s.) study of coenzyme F430 from Methanobacterium thermoautotrophicum

1985 ◽  
Vol 232 (1) ◽  
pp. 281-284 ◽  
Author(s):  
G P Diakun ◽  
B Piggott ◽  
H J Tinton ◽  
D Ankel-Fuchs ◽  
R K Thauer
Keyword(s):  
Fine Structure ◽  
Methanobacterium Thermoautotrophicum ◽  
Methanogenic Bacteria ◽  
Model Compounds ◽  
X Ray ◽  
Absorption Fine ◽  
Coenzyme F430 ◽  
X Ray Absorption

Coenzyme F430 is a nickel porphinoid found in all methanogenic bacteria. Extended-X-ray-absorption-fine-structure (e.x.a.f.s.) spectra have been recorded above the nickel K-edge of coenzyme F430 and two model compounds, (5,10,15,20-tetramethylporphinato) nickel(II) and (5,10,15,20-tetramethylchlorinato)-nickel(II). The results show that the four nickel-nitrogen distances in F430 are split, with two nitrogen atoms at 0.192 nm and two at 0.210 nm.

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