Isoflavonoid synthase

Isoflavonoid synthase
Identifiers
EC no.1.14.14.87
Databases
BRENDAenzyme data
ExPASyNiceZyme view
KEGGenzyme entry
MetaCycmetabolic pathway
Rheareactions
PDB structuresRCSB PDB PDBe PDBsum
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PMCarticles
PubMedarticles
NCBIproteins

2-hydroxyisoflavanone synthase (EC 1.14.14.87, CYT93C, IFS, isoflavonoid synthase) is an enzyme with systematic name liquiritigenin,NADPH:oxygen oxidoreductase (hydroxylating, aryl migration).[1][2] It catalyses a rearrangement reaction which converts flavonoids into isoflavones, for example:

+ NADPH + H+
 
 
O2
H2O
Rightward reaction arrow with minor substrate(s) from top left and minor product(s) to top right
 
 
 
2D representation of the chemical structure of Q27123131.
2,4',7-trihydroxyisoflavanone
 

The product 2,4',7-trihydroxyisoflavanone is unstable and loses water, either spontaneously or by the action of 2-hydroxyisoflavanone dehydratase, giving daidzein.[3]

2D representation of the chemical structure of Q27123131.
2,4',7-trihydroxyisoflavanone
 
 
H2O
Rightward reaction arrow with minor product(s) to top right
 
 
 

The enzyme can also act on naringenin, leading to the isoflavone genistein.{[4]

 
 
 
Rightward reaction arrow
 
 
 
2,4',5,7-tetrahydroxyisoflavanone
 
 
 
 
Rightward reaction arrow
 
 
 

Isoflavonoid synthase is a cytochrome P450 protein containing heme. It requires a partner cytochrome P450 reductase for functional expression. This uses nicotinamide adenine dinucleotide phosphate (NADPH).[5]

References

  1. ↑ Hashim MF, Hakamatsuka T, Ebizuka Y, Sankawa U (October 1990). "Reaction mechanism of oxidative rearrangement of flavanone in isoflavone biosynthesis". FEBS Letters. 271 (1–2): 219–22. Bibcode:1990FEBSL.271..219H. doi:10.1016/0014-5793(90)80410-k. PMID 2226805.
  2. ↑ Sawada Y, Ayabe S (May 2005). "Multiple mutagenesis of P450 isoflavonoid synthase reveals a key active-site residue". Biochemical and Biophysical Research Communications. 330 (3): 907–13. Bibcode:2005BBRC..330..907S. doi:10.1016/j.bbrc.2005.03.053. PMID 15809082.
  3. ↑ Hakamatsuka, Takashi; Mori, Kazumi; Ishida, Shinichi; Ebizuka, Yutaka; Sankawa, Ushio (1998). "Purification of 2-Hydroxyisoflavanone Dehydratase from the Cell Cultures of Pueraria Lobata". Phytochemistry. 49 (2): 497–505. doi:10.1016/S0031-9422(98)00266-0.
  4. ↑ Enzyme 1.14.14.87 at KEGG Pathway Database.
  5. ↑ Sawada Y, Kinoshita K, Akashi T, Aoki T, Ayabe S (September 2002). "Key amino acid residues required for aryl migration catalysed by the cytochrome P450 2-hydroxyisoflavanone synthase". The Plant Journal. 31 (5): 555–64. doi:10.1046/j.1365-313x.2002.01378.x. PMID 12207646.