title: Identification of a novel dihydrodaidzein racemase essential for biosynthesis of equol from daidzein in Lactococcus sp. strain 20-92.
abstract: Equol is metabolized from daidzein, a soy isoflavone, by the gut microflora. In this study, we identified a novel dihydrodaidzein racemase (L-DDRC) that is involved in equol biosynthesis in a lactic acid bacterium, Lactococcus sp. strain 20-92, and confirmed that histidine-tagged recombinant L-DDRC (L-DDRC-His) was able to convert both the (R)- and (S)-enantiomers of dihydrodaidzein to the racemate. Moreover, we showed that recombinant L-DDRC-His was essential for in vitro equol production from daidzein by a recombinant enzyme mixture and that efficient in vitro equol production from daidzein was possible using at least four enzymes, including L-DDRC. We also proposed a model of the metabolic pathway from daidzein to equol in Lactococcus strain 20-92.
authors.affiliation: Institute of Biomedical Innovation, Otsuka Pharmaceutical Co., Ltd., Tokushima, Japan. yshimada@research.otsuka.co.jp
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Shimada
authors.forename: Masayuki
authors.initials: M
authors.lastname: Takahashi
authors.forename: Norihiro
authors.initials: N
authors.lastname: Miyazawa
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Abiru
authors.forename: Shigeto
authors.initials: S
authors.lastname: Uchiyama
authors.forename: Haretsugu
authors.initials: H
authors.lastname: Hishigaki
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D060754:Equol / Q000096:biosynthesis*; D007529:Isoflavones / Q000378:metabolism*; D017045:Lactococcus / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D053858:Metabolic Networks and Pathways; D008969:Molecular Sequence Data; D019998:Racemases and Epimerases / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013237:Stereoisomerism
chemical_list: D001426:Bacterial Proteins; D007529:Isoflavones; D011994:Recombinant Proteins; C433163:dihydrodaidzein; D060754:Equol; C004742:daidzein; D019998:Racemases and Epimerases