title: Monitoring key reactions in degradation of chloroaromatics by in situ (1)H nuclear magnetic resonance: solution structures of metabolites formed from cis-dienelactone.
abstract: A (1)H nuclear magnetic resonance ((1)H NMR) assay was used to study the enzymatic transformation of cis-dienelactone, a central intermediate in the degradation of chloroaromatics. It was shown that the product of the cis-dienelactone hydrolase reaction is maleylacetate, in which there is no evidence for the formation of 3-hydroxymuconate. Under acidic conditions, the product structure was 4-carboxymethyl-4-hydroxybut-2-en-4-olide. Maleylacetate was transformed by maleylacetate reductase into 3-oxoadipate, a reaction competing with spontaneous decarboxylation into cis-acetylacrylate. One-dimensional (1)H NMR in (1)H(2)O could thus be shown to be an excellent noninvasive tool for monitoring enzyme activities and assessing the solution structure of substrates and products.
authors.affiliation: Division of Microbiology, GBF-German Research Center for Biotechnology, Mascheroder Weg 1, D-38124 Braunschweig, Germany. dpi@gbf.de
authors.forename: Dietmar H
authors.initials: DH
authors.lastname: Pieper
authors.forename: Katrin
authors.initials: K
authors.lastname: Pollmann
authors.forename: Patricia
authors.initials: P
authors.lastname: Nikodem
authors.forename: Bernardo
authors.initials: B
authors.lastname: Gonzalez
authors.forename: Victor
authors.initials: V
authors.lastname: Wray
mesh_terms: D001673:Biodegradation, Environmental; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism; D020118:Cupriavidus necator / Q000201:enzymology* / Q000254:growth & development; D006859:Hydrogen / Q000378:metabolism; D007783:Lactones / Q000737:chemistry / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008298:Maleates / Q000378:metabolism*; D010088:Oxidoreductases / Q000378:metabolism; D044925:Oxidoreductases Acting on CH-CH Group Donors
chemical_list: D007783:Lactones; D008298:Maleates; C084081:dienelactone; C011905:maleoylacetic acid; D006859:Hydrogen; D010088:Oxidoreductases; D044925:Oxidoreductases Acting on CH-CH Group Donors; C021530:maleylacetate reductase; D002265:Carboxylic Ester Hydrolases; C046130:carboxymethylenebutenolidase