中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
—— | 1(E),2(E)-di-O-sinapoyl β-D-glucopyranoside | 91095-79-3 | C28H32O14 | 592.554 |
Members of the Brassicaceae family accumulate specific sinapate esters, i.e. sinapoylcholine (sinapine), which is considered as a major antinutritive compound in seeds of important crop plants like
Glucosylation of anthocyanin in carnations (Dianthus caryophyllus) and delphiniums (Delphinium grandiflorum) involves novel sugar donors, aromatic acyl-glucoses, in a reaction catalyzed by the enzymes acyl-glucose–dependent anthocyanin 5(7)-O-glucosyltransferase (AA5GT and AA7GT). The AA5GT enzyme was purified from carnation petals, and cDNAs encoding carnation Dc AA5GT and the delphinium homolog Dg AA7GT were isolated. Recombinant Dc AA5GT and Dg AA7GT proteins showed AA5GT and AA7GT activities in vitro. Although expression of Dc AA5GT in developing carnation petals was highest at early stages, AA5GT activity and anthocyanin accumulation continued to increase during later stages. Neither Dc AA5GT expression nor AA5GT activity was observed in the petals of mutant carnations; these petals accumulated anthocyanin lacking the glucosyl moiety at the 5 position. Transient expression of Dc AA5GT in petal cells of mutant carnations is expected to result in the transfer of a glucose moiety to the 5 position of anthocyanin. The amino acid sequences of Dc AA5GT and Dg AA7GT showed high similarity to glycoside hydrolase family 1 proteins, which typically act as β-glycosidases. A phylogenetic analysis of the amino acid sequences suggested that other plant species are likely to have similar acyl-glucose–dependent glucosyltransferases.
石竹(Dianthus caryophyllus)和翠雀花(Delphinium grandiflorum)中花青素的葡萄糖化涉及新型糖基供体,芳香基酰基葡萄糖,由酰基葡萄糖依赖的花青素5(7)-O-葡萄糖基转移酶(AA5GT和AA7GT)催化反应。从石竹花瓣中纯化了AA5GT酶,并分离了编码石竹Dc AA5GT和翠雀花同源物Dg AA7GT的cDNA。重组的Dc AA5GT和Dg AA7GT蛋白在体外表现出AA5GT和AA7GT活性。虽然Dc AA5GT在石竹花瓣的发育早期表达最高,但AA5GT活性和花青素积累在后期仍然持续增加。在突变石竹花瓣中,既没有观察到Dc AA5GT表达,也没有AA5GT活性;这些花瓣积累了缺乏5位葡萄糖基的花青素。预计在突变石竹花瓣细胞中短暂表达Dc AA5GT将导致将葡萄糖基转移至花青素的5位。Dc AA5GT和Dg AA7GT的氨基酸序列与糖苷水解酶家族1蛋白的高度相似,这些蛋白通常作为β-葡萄糖苷酶。氨基酸序列的系统发育分析表明,其他植物物种可能具有类似的酰基葡萄糖依赖性葡萄糖转移酶。