Biosynthesis of galactogen: identification of a beta-(1----6)-D-galactosyltransferase in Helix pomatia albumen glands.
Biosynthesis of galactogen: identification of a beta-(1----6)-D-galactosyltransferase in Helix pomatia albumen glands.
复制标题
半乳糖原的生物合成：螺旋波马蒂亚蛋白腺中β-(1----6)-D-半乳糖基转移酶的鉴定。
DOI：
10.1016/0304-4165(89)90087-1
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Blake,DA
中科院分区：
文献类型：
--
作者：
Goudsmit,EM;Ketchum,PA;Grossens,MK;Blake,DA
用UDP-对氨基苯-Sepharose亲和层析法纯化了β-（1→ 6）-D-半乳糖基转移酶，纯化倍数达2000倍以上。该酶来自苹果清蛋白腺的沉淀级分（8000× g），催化D-半乳糖从UDP-半乳糖转移到受体H上的（1→ 6）键。果浆其他三种聚合物作为受体：牛肺半乳聚糖，Stagnaea galactogen和阿拉伯半乳聚糖从落叶松木材。为了确定酶的连接特异性，将其与UDP-d-半乳糖和受体半乳糖原一起孵育，所述受体半乳糖原先前已通过用半乳糖氧化酶和[3 H] KBH 4处理而被氚化。回收的[3 H]半乳糖原反应产物，甲基化，水解和乙酰化，氚化衍生物进行了鉴定，通过气相色谱分离的流出物馏分的质谱。该分析表明，（1→ 6）-连接的半乳糖基已被添加到酶处理的受体半乳糖原上。还鉴定了一种水解酶，可从H.果浆
Abstract A β-(1→ 6)-d-galactosyltransferase has been purified over 2000-fold by affinity chromatography on UDP-p-aminophenyl-Sepharose. The enzyme, from a pellet fraction (8000× g) of Helix pomatia albumen gland, catalyzes transfer of d-galactose from UDP-galactose to a (1→ 6) linkage on acceptor H. pomatia galactogen. Three other polymers served as acceptors: beef lung galactan, Lymnaea stagnalis galactogen and arabinogalactan from larch wood. To determine the linkage specificity of the enzyme, it was incubated with UDP-d-galactose and acceptor galactogen that had been tritiated previously by treatment with galactose oxidase and [3 H] KBH 4. The [3 H] galactogen reaction product was recovered, methylated, hydrolyzed and acetylated; tritiated derivatives were identified by mass spectroscopy of effluent fractions separated by gas chromatography. This analysis revealed that (1→ 6)-linked galactosyl groups had been added to the enzyme-treated acceptor galactogen. Also identified was a hydrolytic enzyme that removed terminal α1, 2-linked l-galactosyl residues from H. pomatia galactogen.