Department of Food Science and Technology, College of Agriculture and Life Sciences, Jeonbuk National University, Jeonju 54896, Republic of Korea.
School of Pharmacy and Institute of New Drug Development, Jeonbuk National University, Jeonju 54896, Republic of Korea.
Food Chem. 2024 Aug 1;448:139182. doi: 10.1016/j.foodchem.2024.139182. Epub 2024 Mar 30.
Amylosucrase (ASase) efficiently biosynthesizes α-glucoside using flavonoids as acceptor molecules and sucrose as a donor molecule. Here, ASase from Deinococcus wulumuqiensis (DwAS) biosynthesized more naringenin α-glucoside (NαG) with sucrose and naringenin as donor and acceptor molecules, respectively, than other ASases from Deinococcus sp. The biotransformation rate of DwAS to NαG was 21.3% compared to 7.1-16.2% for other ASases. Docking simulations showed that the active site of DwAS was more accessible to naringenin than those of others. The 217th valine in DwAS corresponded to the 221 isoleucine in Deinococcus geothermalis AS (DgAS), and the isoleucine possibly prevented naringenin from accessing the active site. The DwAS-V217I mutant had a significantly lower biosynthetic rate of NαG than DwAS. The k/K value of DwAS with naringenin as the donor was significantly higher than that of DgAS and DwAS-V217I. In addition, NαG inhibited human intestinal α-glucosidase more efficiently than naringenin.
支链淀粉酶（ASase）能够有效地利用黄酮类化合物作为受体分子，蔗糖作为供体分子来生物合成α-糖苷。在这里，来自生酮球菌（Deinococcus wulumuqiensis）的 ASase（DwAS）与其他来自生酮球菌属的 ASase 相比，分别用蔗糖和柚皮素作为供体和受体分子，生物合成了更多的柚皮素α-葡萄糖苷（NαG）。与其他 ASase 相比，DwAS 转化为 NαG 的转化率为 21.3%。对接模拟表明，DwAS 的活性位点比其他 ASase 更容易接近柚皮素。DwAS 中的第 217 位缬氨酸对应于地热能生酮球菌 AS（DgAS）中的第 221 位异亮氨酸，而该异亮氨酸可能阻止了柚皮素进入活性位点。DwAS-V217I 突变体生物合成 NαG 的速率明显低于 DwAS。DwAS 与柚皮素作为供体的 k/K 值明显高于 DgAS 和 DwAS-V217I。此外，NαG 对人肠α-葡萄糖苷酶的抑制作用比柚皮素更有效。
