UDP-Glucose: Cyanidin 3-O-glucosyltransferase from cell cultures of Haplopappus gracilis

Abstract

From cell cultures of Haplopappus gracilis, an enzyme, catalyzing the glucosylation of cyanidin at the 3 position using uridine diphosphate-D-glucose (UDPG) as glucosyl-donor, has been isolated and purified 50-fold. The enzyme was not specific for cyanidin alone, but also glucosylated other anthocyanidins and flavonols in position 3. However, apigenin, luteolin, naringenin and dihydroquercetin were not glucosylated. The reaction has an optimum pH of approximately 8, and the apparent K m values for UDPG and cyanidin were 0.5 and 0.33 mM respectively. The enzyme reaction is strongly inhibited by cyanidin (above 0.25 mM).

Purification and Properties of Flavonol-Ring B Glucosyltransferase from Chrysosplenium americanum

“…Glucosyltransferase activity of C. americanum exhibited no requirement for divalent cations which compared well with some reported glucosyltransferases (12,14) but is in contrast with that of C-glycoflavones (3). The substrate specificity expressed by this enzyme and the low Km values for its flavonoid substrates and the cosubstrate UDP-glucose indicate high affinity as compared with other flavonoid glucosyltransferases (17,21,22).…”

“…flavones, isoflavones, flavonols, and anthocyanidins (18,22,23). Position specificity has also been reported for the 7-O-glucosyltransferases of flavones, isoflavones, and flavonols (18,23,24), as well as the much investigated 3-O-glucosyltransferases of flavonols and anthocyanidins (21)(22)(23)(24). No glucosyltransferase specific for ring B of flavonoids has, so far, been reported except for the detection of a weak glucosylating activity for positions 5,7, and 3' of the flavonol quercetin by nonpurified extracts of Zea mays (7).…”

Identification, recombinant expression, and biochemical characterization of a flavonol 3-O-glucosyltransferase clone from Citrus paradisi

“…It is important to note that the majority of flavonol GT activity was removed through a hydroxyapatite column purification step, even as one of the subsequent Mono Q-purified samples could also glucosylate flavonol substrates. It was noted that this sample likely still contained multiple GTs with similar chromatographic properties as it had activity with the flavonol substrates quercetin (6) greatly with values ranging from 0.9 to 400 lM reported (e.g., Saleh et al, 1976;Jourdan and Mansell, 1982;Kleinehollenhorst et al, 1982;. Apparent K m values for UDP-glucose tend to be higher than for the corresponding flavonoid substrates, and contrast greatly with values ranging from 43 to 1880 lM reported (e.g., Ford et al, 1998;Yamazaki et al, 1999;Taguchi et al, 2003;Noguchi et al, 2007).…”

Biosynthesis of vancomycin: identification of TDP-glucose: aglycosyl-vancomycin glucosyltransferase from Amycolatopsis orientalis

“…The pH optimum for the enzyme is in accord with that found for glucosyltransferases from plant tissue. Flavonol glucosyltransferases isolated from various sources have pH optima between 8.0 and 133 9.0 [6][7][8]. While the optimum pH for activity of our enzyme is 9.0, stability problems resulted when the enzyme was stored at pH 9 and 4°C (data not shown).…”