Biosynthesis of the carbohydrate moieties of arabinogalactan proteins by membrane-bound β-glucuronosyltransferases from radish primary roots.
Biosynthesis of the carbohydrate moieties of arabinogalactan proteins by membrane-bound β-glucuronosyltransferases from radish primary roots.
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DOI：
10.1007/s00425-013-1959-0
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发表时间：
2013-12
期刊：
影响因子：
4.3
通讯作者：
Tsumuraya Y
中科院分区：
文献类型：
--
作者：
Endo M;Kotake T;Watanabe Y;Kimura K;Tsumuraya Y
来自黄化 6 天的萝卜根 (Raphanus sativus L. var hortensis) 的膜部分含有参与阿拉伯半乳聚糖蛋白 (AGP) 碳水化合物部分合成的 β-葡萄糖醛酸基转移酶 (GlcAT)。 GlcAT 将 [14C]GlcA 从 UDP-[14C]GlcA 转移到 β-(1 → 3)-半乳聚糖上作为外源受体底物，比活性为 50–150 pmol min−1（毫克蛋白质）−1。该酶样本还催化 [14C]GlcA 转移到来自成熟萝卜根的酶促修饰的 AGP 上。对转移产物的分析表明，[14C]GlcA 的转移优先发生在连续的 (1→3) 连接的 β-Gal 链以及通过 β-(1→6) 连接的单支链 β-(1→6)-Gal 残基上，产生支链酸性侧链。这些酶还将 [14C]GlcA 残基转移到几种寡糖上，例如 β-(1 → 6)- 和 β-(1 → 3)-半乳三糖。三糖α-l-Araf-(1→3)-β-Gal-(1→6)-Gal是良好的受体，产生支链四糖α-l-Araf-(1→3)[β-GlcA-(1→6)]-β-Gal-(1→6)-Gal。我们报告了第一个参与 AG 合成的 β-GlcAT 体外测定系统，这是迈向全面表征和克隆的一步。本文的在线版本 (doi:10.1007/s00425-013-1959-0) 包含补充材料，可供授权用户使用。
A membrane fraction from etiolated 6-day-old primary radish roots (Raphanus sativus L. var hortensis) contained β-glucuronosyltransferases (GlcATs) involved in the synthesis of the carbohydrate moieties of arabinogalactan proteins (AGPs). The GlcATs transferred [14C]GlcA from UDP-[14C]GlcA on to β-(1 → 3)-galactan as an exogenous acceptor substrate, giving a specific activity of 50–150 pmol min−1 (mg protein)−1. The enzyme specimen also catalyzed the transfer of [14C]GlcA on to an enzymatically modified AGP from mature radish root. Analysis of the transfer products revealed that the transfer of [14C]GlcA occurred preferentially on to consecutive (1 → 3)-linked β-Gal chains as well as single branched β-(1 → 6)-Gal residues through β-(1 → 6) linkages, producing branched acidic side chains. The enzymes also transferred [14C]GlcA residues on to several oligosaccharides, such as β-(1 → 6)- and β-(1 → 3)-galactotrioses. A trisaccharide, α-l-Araf-(1 → 3)-β-Gal-(1 → 6)-Gal, was a good acceptor, yielding a branched tetrasaccharide, α-l-Araf-(1 → 3)[β-GlcA-(1 → 6)]-β-Gal-(1 → 6)-Gal. We report the first in vitro assay system for β-GlcATs involved in the AG synthesis as a step toward full characterization and cloning. The online version of this article (doi:10.1007/s00425-013-1959-0) contains supplementary material, which is available to authorized users.
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影响因子：
3.1
作者：
ALBERSHEIM, PETER;NEVINS, DONALD J.;KARR, ARTHUR
通讯作者：
KARR, ARTHUR
DOI：
10.1039/jr9580004408
发表时间：
1958-01-01
期刊：
JOURNAL OF THE CHEMICAL SOCIETY
影响因子：
--
作者：
ASPINALL, GO;AURET, BJ;HIRST, EL
通讯作者：
HIRST, EL
影响因子：
7.4
作者：
Oka, Takuji;Saito, Fumie;Jigami, Yoshifumi
通讯作者：
Jigami, Yoshifumi
影响因子：
7.4
作者：
Tryfona, Theodora;Liang, Hui-Chung;Dupree, Paul
通讯作者：
Dupree, Paul
影响因子：
7.4
作者：
SEKIMATA, M;OGURA, K;YAMAMOTO, S
通讯作者：
YAMAMOTO, S