Flavanone-specific 7-O-glucosyltransferase activity in Citrus paradisi seedlings: purification and characterization

Arch Biochem Biophys. 1990 Oct;282(1):50-7. doi: 10.1016/0003-9861(90)90085-d.

Abstract

The isolation and characterization of a flavanone-specific 7-O-glucosyltransferase and its resolution from other glucosyltransferases in Citrus paradisi (grapefruit) seedlings is described. This new enzyme in the subclass 2.4.1 catalyzes the glucosylation of the 7-OH group of naringenin (4',5',7-trihydroxyflavanone) to prunin and has been purified (943-fold) by fractional precipitation with ammonium sulfate and successive chromatography on Sephadex G-100, hydroxyapatite, UDP-glucuronic acid agarose, Mono Q, and Mono P columns. It has a pH optimum of 7.5-8.0, an apparent pI of 4.3, and an apparent Mr of 54,900. This glucosyltransferase has an expressed specificity for the 7-position of the flavanones naringenin (Kmapp 62 microM; Kmapp UDPG 51 microM) and hesperetin (Kmapp 124 microM; Kmapp UDPG 243 microM) and did not accept other flavone or flavonol aglycones. Characteristics of other flavonoid glucosyltransferase activities found in grapefruit seedlings are also described.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ammonium Sulfate
  • Chromatography
  • Chromatography, Affinity
  • Chromatography, Gel
  • Chromatography, Ion Exchange
  • Durapatite
  • Electrophoresis, Polyacrylamide Gel
  • Fruit
  • Glucosyltransferases / isolation & purification*
  • Glucosyltransferases / metabolism
  • Hydroxyapatites
  • Kinetics
  • Molecular Weight
  • Plants / enzymology*
  • Substrate Specificity

Substances

  • Hydroxyapatites
  • Durapatite
  • Glucosyltransferases
  • flavanone 7-O-beta-glucosyltransferase
  • Ammonium Sulfate