Journal ArticleDOI
Biodehalogenation: reactions of cytochrome P-450 with polyhalomethanes.
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TLDR
The results establish that P. putida is a valid whole cell model for the reductase activity of the P-450 complement in these reactions, and the chemistry observed for the enzyme parallels that of its iron(II) porphyrin active site.Abstract:
The products, stoichiometry, and kinetics of the oxidation of the enzyme cytochrome P-450 cam by five polyhalomethanes and chloronitromethane are described. The reactivity of the enzyme is compared with that of deuteroheme and with the enzyme in its native cell, Pseudomonas putida (PpG-786). In all cases, the reaction entails hydrogenolysis of the carbon-halogen bond: 2FeIIP + RCXn----2FeIIIP + RCHXn-1 (P = porphyrin or P-450 cam in vitro and in vivo). Trichloronitromethane was the fastest reacting substrate, and chloroform was the slowest. The results establish that P. putida is a valid whole cell model for the reductase activity of the P-450 complement in these reactions. The reactions of cytochrome P-450 with polyhaloalkanes proceed in a manner quite analogous to other iron(II) proteins in the G conformation. The chemistry observed for the enzyme parallels that of its iron(II) porphyrin active site. Iron-bonded carbenes are not intermediates, and hydrolytically stable iron alkyls are not products of these reactions.read more
Citations
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Journal ArticleDOI
Microbial reductive dehalogenation.
William W. Mohn,James M. Tiedje +1 more
TL;DR: Agarwal et al. as mentioned in this paper used Desulfomonile tiedjei DCB-1 as a model to understand reductive dehalogenating organisms in undefined, syntrophic anaerobic communities.
Journal ArticleDOI
Reductive Elimination of Chlorinated Ethylenes by Zero-Valent Metals
TL;DR: In this article, it was shown that reductive β-elimination reactions of halogenated ethylenes are comparable energetically to hydrogenolysis at neutral pH and that such pathways may be involved in the reaction of chloroethylenes with zero-valent metals.
Journal ArticleDOI
Bacterial dehalogenases: biochemistry, genetics, and biotechnological applications.
Susanne Fetzner,Franz Lingens +1 more
TL;DR: This review is a survey of bacterial dehalogenases that catalyze the cleavage of halogen substituents from haloaromatics, haloalkanes, h Haloalcohols, and h Haloalkanoic acids.
Book ChapterDOI
Inhibition of Cytochrome P450 Enzymes
TL;DR: Cytochrome P450s (P450s) are subject to inhibition/inactivation by various chemically diverse agents, which may interact directly or indirectly with either the P450 prosthetic heme or the protein moiety or with both moieties.
Journal ArticleDOI
Variations on a (t)heme--novel mechanisms, redox partners and catalytic functions in the cytochrome P450 superfamily.
TL;DR: The catalytic potential of the P450s in organic biotransformations is the subject of this review—with emphasis on the breadth of P450 redox systems now recognised and the catalytic versatility of these biotechnologically important enzymes.
References
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Journal ArticleDOI
Chemical mechanisms of catalysis by cytochromes P-450: a unified view
Book ChapterDOI
Bacterial P-450cam methylene monooxygenase components: cytochrome m, putidaredoxin, and putidaredoxin reductase.
TL;DR: The procedures outlined in the chapter provide a reproducible isolation in gram quantities of pure components of the camphor 5-monooxygenase system from P. putida strain PpG 786.
Journal ArticleDOI
Oxidation of trichloroethylene by liver microsomal cytochrome P-450: evidence for chlorine migration in a transition state not involving trichloroethylene oxide.
Miller Re,Guengerich Fp +1 more
TL;DR: The kinetic data and the discrepancies between the observed metabolites and TCE oxide breakdown products support the view that the epoxide is not an obligate intermediate in the formation of chloral, and an alternative model is presented in which chlorine migration occurs in an oxygenated TCE-cytochrome P-450 transition state.
Journal ArticleDOI
Binding of 14C-Carbon Tetrachloride to Microsomal Proteins in vitro and Formation of CHCl3 by Reduced Liver Microsomes
TL;DR: The first step in CCl4 liver toxicity is the very rapid formation of fast reacting intermediates, which bind to liver lipids and proteins and also initiate lipid peroxidation.
Journal ArticleDOI
The mechanism of reductive dehalogenation of halothane by liver cytochrome P450.
TL;DR: From results a reaction pathway could be derived which includes radical and carbanion intermediates as reactive precursors of CTE and CDE, respectively.