title: Properties and genetic control of anthocyanin 5-O-glucosyltransferase in flowers of Petunia hybrida.
abstract: An anthocyanin 5-O-glucosyltransferase from flowers of Petunia hybrida was purified about 30-fold. Using uridine 5'-diphosphoglucose as glucose donor (Km 0.22 mM), the enzyme glucosylated the 3-(p-coumaroyl)-rutinoside derivatives of delphinidin and petunidin (Km 3 μM), isolated from pollen of Petunia. Delphinidin 3-rutinoside, cyanidin 3-rutinoside and delphinidin 3-glucoside did not serve as substrates. The glucosylation of petunidin 3-(p-coumaroyl)-rutinoside showed a pH-activity optimum at pH 8.3 and was neither stimulated by Mg(2+) or Ca(2+), nor inhibited by ethylenediaminetetraacetic acid. After separating the 5-O-glucosyltransferase from the anthocyanidin 3-O-glucosyltransferase by means of chromatofocusing, it was shown that both enzymes exhibit a high degree of positional specificity. The 5-O-glucosyltransferase activity was correlated with the gene An1, but not with the gene Gf.
authors.affiliation: Research Section 'Biosynthesis of Flavonoids', Department of Plant Physiology, University of Amsterdam, Kruislaan 318, NL-1098 SM, Amsterdam, The Netherlands.
authors.forename: L M
authors.initials: LM
authors.lastname: Jonsson
authors.forename: M E
authors.initials: ME
authors.lastname: Aarsman
authors.forename: J
authors.initials: J
authors.lastname: van Diepen
authors.forename: P
authors.initials: P
authors.lastname: de Vlaming
authors.forename: N
authors.initials: N
authors.lastname: Smit
authors.forename: A W
authors.initials: AW
authors.lastname: Schram