title: A-ring ortho-specific monohydroxylation of daidzein by cytochrome P450s of Nocardia farcinica IFM10152.
abstract: The bioconversion of the isoflavonoid daidzein using whole cell Nocardia farcinica IFM10152 showed two kinds of major metabolic modifications, i.e. mono-hydroxylation and subsequent O-methylation. The major hydroxylated products of daidzein prior to the O-methylation reaction were 3',4',7-trihydroxyisoflavone (3'-ODI), 4',6,7-trihydroxyisoflavone (6-ODI) and 4',7,8-trihydroxyisoflavone (8-ODI), which are mono-hydroxylated at the ortho position of each hydroxyl group of daidzein. To identify monooxygenases playing a key role in the monohydroxylation of the A-ring of daidzein, all genes of 27 cytochrome P450s from N. farcinica IFM10152 were cloned and transformed into a E. coli BL21 (DE3) host system. By this enzymatic reaction using the mutants and the genome sequence analysis of N. farcinica IFM10152, it was revealed that nfa12130 and nfa33880 P450 genes clustered with their own ferredoxins and ferredoxin reductases (nfa12140+nfa12150 and nfa338870+nfa33860, respectively) are responsible for the hydroxylation of the A-ring of daidzein, and their major reaction products were 6-ODI and 8-ODI, respectively.
authors.affiliation: School of Chemical and Biological Engineering, Institute of Molecular Biology and Genetics and Institute of Bioengineering, Seoul National University, Seoul, South Korea.
authors.forename: Kwon-Young
authors.initials: KY
authors.lastname: Choi
authors.forename: Tae-Jin
authors.initials: TJ
authors.lastname: Kim
authors.forename: Sung-Ki
authors.initials: SK
authors.lastname: Koh
authors.forename: Chang-Hyun
authors.initials: CH
authors.lastname: Roh
authors.forename: Bishnu Prasad
authors.initials: BP
authors.lastname: Pandey
authors.forename: Nahum
authors.initials: N
authors.lastname: Lee
authors.forename: Byung-Gee
authors.initials: BG
authors.lastname: Kim
mesh_terms: D001711:Biotransformation; D002248:Carbon Monoxide / Q000737:chemistry / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D006900:Hydroxylation; D007529:Isoflavones / Q000737:chemistry / Q000378:metabolism*; D009615:Nocardia / Q000201:enzymology* / Q000235:genetics*
chemical_list: D007529:Isoflavones; C004742:daidzein; D002248:Carbon Monoxide; D003577:Cytochrome P-450 Enzyme System