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

Purification of limonoid glucosyltransferase from navel orange albedo tissues

“…Glucosyltransferase from plant sources that utilize flavonoids and other small molecules as substrates are generally single subunit enzymes, are acidic proteins and fall in the Mr range of 40-60 k [5,[8][9][10][11][12][13][14][15][16][17][18]. The limonoid GTase isolated from navel oranges in this report has an Mr close to that of two other transferases isolated from Citrus sp.…”

“…The enzyme activity occurred in the Mr range of 4(~60 k was determined by SDS-PAGE. Nucleotide sugar affinity chromatography has been used successfully in the purification scheme for a ftavanone-specific 7-O-glucosyltransferase from grapefruit [5] and the purification of a UDP-glucosyltransferase from liver microsomes [6]. The enzyme fraction obtained from the UDP-glucuronic acid affinity column was applied to a DEAE ion exchange HPLC and run at pH 7.…”

“…The limonoid GTase isolated from navel oranges in this report has an Mr close to that of two other transferases isolated from Citrus sp. The flavanone glucosyltransferase from pummelo leaves has a reported Mr of 52 k [15] and a flavanone glucosyltransferase from grapefruit seeds has a reported Mr of 54.9 k [5].…”

Cloning and characterization of a glucosyltransferase that reacts on 7-hydroxyl group of flavonol and 3-hydroxyl group of coumarin from tobacco cells

“…There are some reports concerning the K m values of flavonoids with F7GTs; that of 7-OH of baicalein with a recombinant enzyme of baicalein 7-O-glucosyltransferase is 137 µM [14], and those of naringenin and hesperetin with a flavanone-specific F7GT purified from seedlings of grapefruit are 62 µM and124 µM, respectively [28]. The K m value of kaempferol with rNTGT2 is 6.5 µM, indicates its sufficient affinity to the substrate.…”

Juvenile-Specific Localization and Accumulation of a Rhamnosyltransferase and Its Bitter Flavonoid in Foliage, Flowers, and Young Citrus Fruits

“…Hesperetin is then glucosylated to hesperitin-7-O-glucoside (Lewinsohn et al, 1989b;McIntosh et al, 1990) and is finally rhamnosylated to neohesperidin by the same rhamnosyltransferase, producing naringin (Lewinsohn et al, 1989b;Bar-Peled et al, 1991). The accumulation and distribution of the major flavanoneglycoside products have been investigated during different stages of growth of grapefruit and sour orange without parallel studies of the enzymes involved.…”