Common Identity of UDP-Glucose: Anthocyanidin 3-O-Glucosyltransferase and UDP-Glucose: Flavonol 3-O-Glucosyltransferase in Flowers of Petunia hybrida
| Autor: | Wilma E. Donker-Koopman, A. G. M. Gerats, Johan Bastiaannet, Mirjam E. G. Aarsman, AndréW. Schram, L. M. V. Jonsson |
|---|---|
| Rok vydání: | 1984 |
| Předmět: |
chemistry.chemical_classification
UDP Glucose biology Metabolism biology.organism_classification General Biochemistry Genetics and Molecular Biology Petunia hybrida chemistry.chemical_compound Enzyme chemistry Biochemistry Anthocyanin Botany biology.protein Glucosyltransferase Anthocyanidin 3-O-glucosyltransferase Solanaceae |
| Zdroj: | Zeitschrift für Naturforschung C. 39:559-567 |
| ISSN: | 1865-7125 0939-5075 |
| DOI: | 10.1515/znc-1984-0609 |
| Popis: | In an attempt to distinguish between the UDP-glucose: flavonol 3-O-glucosyltransferase (3GT) and the UDP-glucose: anthocyanidin 3-O-glucosyltransferase in flower buds of Petunia hybrida, several properties of these activities were determined. The 3-glucosylation of anthocyanidin had a pH-activity optimum of 7.2, that of flavonol pH 9.2 to 9.5. Anthocyanidin 3GT activity was lowered in the presence of EDTA or β-mercaptoethanol, but this was due to an effect on the anthocyanidin substrate. The two 3-glucosylating activities were to a similar extent inhibited by an increasing ionic strength in the enzyme assay and showed an identical iso-electric point (5.2) as determined by chromatofocusing. Molecular weights were identical: 26000, 52000 or 78000 daltons as determined by gel-filtration. Antiserum raised against partially purified 3GT gave identical immunoprecipitation curves with flavonol 3GT and anthocyanidin 3GT. Special attention was given to the 3-O-glucosyltransferase in mutants with low levels of 3GT activity. These mutants are unable to form significant amounts of anthocyanins but contain wild- type amounts of flavonols. The enzyme of such mutants had the same iso-electric point and identical titration-curves with antiserum as the enzyme from wildtype plants. 3GT from wildtype or mutant plants glucosylated flavonols at higher rates than anthocyanidins. |
| Databáze: | OpenAIRE |
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