First bacterial chalcone isomerase isolated from Eubacterium ramulus.

Claudia Herles; Annett Braune; Michael Blaut

doi:10.1007/s00203-004-0676-2

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First bacterial chalcone isomerase isolated from Eubacterium ramulus.

Claudia Herles·Annett Braune·Michael Blaut

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Abstract

The human fecal anaerobe Eubacterium ramulus is capable of degrading various flavonoids, including the flavone naringenin. The first step in the proposed degradation pathway is the isomerization of naringenin to the corresponding chalcone. Cell-free extracts of E. ramulus displayed chalcone isomerase activity. The enzyme from E. ramulus was purified to homogeneity. Its apparent molecular mass was estimated to be 136 and 129 kDa according to gel filtration and native polyacrylamide gel electrophoresis, respectively. Chalcone isomerase is composed of one type of subunit of 30 kDa. The purified enzyme catalyzed the isomerization of naringenin chalcone, isoliquiritigenin, and butein, three chalcones that differ in their hydroxylation pattern. N-bromosuccinimide, but also naringenin and phloretin, inhibited the purified enzyme considerably. This is the first report on a bacterial chalcone isomerase. The physiological function of the purified enzyme is unclear, but an involvement in the conversion of the flavanone naringenin to the chalcone is proposed.

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Bromosuccinimide Chalcone Chalcones Chromatography, Gel Electrophoresis, Polyacrylamide Gel Enzyme Inhibitors Eubacterium Flavanones Flavonoids Intramolecular Lyases Isomerism Molecular Weight Phloretin Protein Subunits Substrate Specificity Journal Article Research Support, Non-U.S. Gov't

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Claudia Herles, Annett Braune, Michael Blaut. 2004-05-01. First bacterial chalcone isomerase isolated from Eubacterium ramulus.. https://doi.org/10.1007/s00203-004-0676-2

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