Research Section 'Biosynthesis of Flavonoids', Department of Plant Physiology, University of Amsterdam, Kruislaan 318, NL-1098 SM, Amsterdam, The Netherlands.
Planta. 1984 Mar;160(4):341-7. doi: 10.1007/BF00393415.
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.
从矮牵牛花朵中纯化出一种花色苷 5-O-葡萄糖基转移酶，使其得到约 30 倍的浓缩。该酶以尿苷 5′-二磷酸葡萄糖为葡萄糖供体（Km 值为 0.22 mM），对分离自矮牵牛花粉的飞燕草色素 3-（对香豆酰基）-鼠李糖苷和锦葵色素 3-鼠李糖苷进行葡萄糖基化（Km 值为 3 μM）。飞燕草色素 3-鼠李糖苷、矢车菊素 3-鼠李糖苷和飞燕草色素 3-葡萄糖苷不作为底物。苯甲酰化锦葵色素 3-鼠李糖苷的葡萄糖基化在 pH 8.3 时表现出最佳的 pH 活性，并且不受 Mg2+或 Ca2+的刺激，也不受乙二胺四乙酸的抑制。通过色谱聚焦将 5-O-葡萄糖基转移酶与花色苷 3-O-葡萄糖基转移酶分离后，表明这两种酶都表现出高度的位置特异性。5-O-葡萄糖基转移酶活性与基因 An1 相关，但与基因 Gf 不相关。
