title: Reversal of 2-bromoethanesulfonate inhibition of methanogenesis in Methanosarcina sp.
abstract: 2-Bromoethanesulfonate (BES) inhibition of methanogenesis from methanol by resting-cell suspensions or cell extracts of Methanosarcina was reversed by coenzyme M. BES inhibition of methylcoenzyme M methylreductase activity in cell-free extracts was reversed by methylcoenzyme M but not by coenzyme M. Methanol/coenzyme M methyltransferase activity was not inhibited by 10 microM BES. Inhibition of methylreductase by BES and 3-bromopropionate was competitive with methylcoenzyme M, but inhibition by 2-bromoethanol exhibited mixed kinetics. The Ki values for the inhibitors in cell-free extracts were similar to the concentrations which inhibited intact cells. BES-resistant mutants of strain 227 were apparently permeability mutants because in vitro assays showed that mutant and parent strain methylreductases were equally sensitive to BES.
mesh_terms: D000476:Alkanesulfonates / Q000633:toxicity*; D017738:Alkanesulfonic Acids; D019605:Euryarchaeota / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development*; D007700:Kinetics; D008623:Mercaptoethanol / Q000031:analogs & derivatives*; D015080:Mesna / Q000378:metabolism*; D000432:Methanol / Q000378:metabolism*; D008780:Methyltransferases / Q000378:metabolism*; D010088:Oxidoreductases / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D000476:Alkanesulfonates; D017738:Alkanesulfonic Acids; C018853:2-bromoethanesulfonic acid; D008623:Mercaptoethanol; D010088:Oxidoreductases; C023895:methyl coenzyme M methylreductase; D008780:Methyltransferases; C036890:methanol-2-mercaptoethanesulfonic acid methyltransferase; D015080:Mesna; D000432:Methanol