title: Reductive dechlorination of trichloroethylene by the CO-reduced CO dehydrogenase enzyme complex from Methanosarcina thermophila.
abstract: Trichloroethylene (TCE) was reductively dechlorinated to cis-dichloroethylene, trans-dichloroethylene, 1,1-dichloroethylene, vinyl chloride, and ethylene by the CO-reduced CO dehydrogenase enzyme complex from Methanosarcina thermophila; the apparent Km and Vmax values were 1.7 +/- 0.3 mM TCE and 26.2 +/- 1.7 mol TCE dechlorinated/min/mmol factor III. Factor III also catalysed the dechlorination of TCE when in the presence of titanium(III) citrate; the apparent Km and Vmax values were 1.2 +/- 0.3 mM TCE and 34.9 +/- 3.6 mol TCE dechlorinated/min/mmol factor III. The enzyme complex was resolved into the two-subunit nickel/iron-sulfur (Ni/Fe-S) component and the two-subunit factor III-containing corrinoid/iron-sulfur (Co/Fe-S) component. The Ni/Fe-S component was unable to dechlorinate TCE in the presence of CO; however, reconstitution with the Co/Fe-S component yielded the same dechlorinated products as with the CO dehydrogenase enzyme complex.
authors.affiliation: Virginia Polytechnic Institute and State University, Department of Anaerobic Microbiology, Blacksburg 24061-0305.
authors.forename: P E
authors.initials: PE
authors.lastname: Jablonski
authors.forename: J G
authors.initials: JG
authors.lastname: Ferry
mesh_terms: D000445:Aldehyde Oxidoreductases / Q000378:metabolism*; D002713:Chlorine / Q000378:metabolism; D007700:Kinetics; D017020:Methanosarcina / Q000201:enzymology*; D009097:Multienzyme Complexes / Q000378:metabolism; D010084:Oxidation-Reduction; D014241:Trichloroethylene / Q000378:metabolism*
chemical_list: D009097:Multienzyme Complexes; D014241:Trichloroethylene; D002713:Chlorine; D000445:Aldehyde Oxidoreductases; C019823:carbon monoxide dehydrogenase