Isolation, purification, and characterization of AgUCGalT1, a galactosyltransferase involved in anthocyanin galactosylation in purple celery (Apium graveolens L.)
Autor: | Feng Wang, Ai-Sheng Xiong, Kai Feng, Zhi-Sheng Xu, Jie-Xia Liu, Jing-Wen Li |
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Rok vydání: | 2018 |
Předmět: |
0106 biological sciences
0301 basic medicine Glycosylation Cyanidin Amino Acid Motifs Plant Science 01 natural sciences Anthocyanins 03 medical and health sciences chemistry.chemical_compound Genetics Escherichia coli Food science Phylogeny Apium Plant Proteins Galactosyltransferase Peonidin biology food and beverages Apium graveolens Galactosyltransferases Enzyme assay carbohydrates (lipids) Models Structural Plant Leaves 030104 developmental biology chemistry Anthocyanin biology.protein Kaempferol Sequence Alignment 010606 plant biology & botany |
Zdroj: | Planta. 247(6) |
ISSN: | 1432-2048 |
Popis: | This study showed that a galactosyltransferase, AgUCGalT1, is involved in anthocyanin galactosylation in purple celery. Celery is a well-known vegetable because of its rich nutrients, low calories, and medicinal values. Its petioles and leaf blades are the main organs acting as nutrient sources. UDP-galactose: cyanidin 3-O-galactosyltransferase can transfer the galactosyl moiety from UDP-galactose to the 3-O-position of cyanidin through glycosylation. This process enhances the stability and water solubility of anthocyanins. In the present study, LC–MS data indicated that abundant cyanidin-based anthocyanins accumulated in the petioles of purple celery (‘Nanxuan liuhe purple celery’). A gene encoding UDP-galactose: cyanidin 3-O-galactosyltransferase, namely AgUCGalT1, was isolated from purple celery and expressed in Escherichia coli BL21 (DE3). Sequence alignments revealed that the AgUCGalT1 protein contained a highly conserved putative secondary plant glycosyltransferase (PSPG) motif. The glycosylation product catalyzed by AgUCGalT1 was detected using UPLC equipment. The recombinant AgUCGalT1 had an optimal enzyme activity at 35 °C and pH 8.0, and showed highest enzyme activity toward cyanidin among the enzyme activities involving other substances, namely, peonidin, quercetin, and kaempferol. The expression levels of AgUCGalT1 were positively correlated with the total anthocyanin contents in purple and non-purple celery varieties. Crude enzymes extracted from purple celery exhibited glycosylation ability, whereas crude enzymes obtained from non-purple celery did not have this ability. This work provided evidence as a basis for investigations on the function of AgUCGalT1 in anthocyanin glycosylation in purple celery. |
Databáze: | OpenAIRE |
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