title: A simplified methylcoenzyme M methylreductase assay with artificial electron donors and different preparations of component C from Methanobacterium thermoautotrophicum delta H.
abstract: Different preparations of the methylreductase were tested in a simplified methylcoenzyme M methylreductase assay with artificial electron donors under a nitrogen atmosphere. ATP and Mg2+ stimulated the reaction. Tris(2,2'-bipyridine)ruthenium (II), chromous chloride, chromous acetate, titanium III citrate, 2,8-diaminoacridine, formamidinesulfinic acid, cob(I)alamin (B12s), and dithiothreitol were tested as electron donors; the most effective donor was titanium III citrate. Methylreductase (component C) was prepared by 80% ammonium sulfate precipitation, 70% ammonium sulfate precipitation, phenyl-Sepharose chromatography, Mono Q column chromatography, DEAE-cellulose column chromatography, or tetrahydromethanopterin affinity column chromatography. Methylreductase preparations which were able to catalyze methanogenesis in the simplified reaction mixture contained contaminating proteins. Homogeneous component C obtained from a tetrahydromethanopterin affinity column was not active in the simplified assay but was active in a methylreductase assay that contained additional protein components.
authors: Department of Microbiology, University of Illinois, Urbana 61801.
authors: P L
authors: PL
authors: Hartzell
authors: J C
authors: JC
authors: Escalante-Semerena
authors: T A
authors: TA
authors: Bobik
authors: R S
authors: RS
authors: Wolfe
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D004579:Electron Transport; D019605:Euryarchaeota / Q000201:enzymology*; D008274:Magnesium / Q000494:pharmacology; D009097:Multienzyme Complexes / Q000302:isolation & purification* / Q000378:metabolism; D010088:Oxidoreductases / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D009097:Multienzyme Complexes; D000255:Adenosine Triphosphate; D010088:Oxidoreductases; C023895:methyl coenzyme M methylreductase; D008274:Magnesium