Characterization and membrane organization of beta 1----3- and beta 1----4-galactosyltransferases from human colonic adenocarcinoma cell lines Colo 205 and SW403: basis for preferential synthesis of type 1 chain lacto-series carbohydrate structures.
Characterization and membrane organization of beta 1----3- and beta 1----4-galactosyltransferases from human colonic adenocarcinoma cell lines Colo 205 and SW403: basis for preferential synthesis of type 1 chain lacto-series carbohydrate structures.
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人结肠腺癌细胞系 Colo 205 和 SW403 的 β 1----3- 和 β 1----4-半乳糖基转移酶的表征和膜组织：优先合成 1 型链乳糖系列碳水化合物结构的基础。
DOI：
10.1016/0003-9861(89)90546-8
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发表时间：
1989
影响因子：
3.9
通讯作者：
Holmes,EH
中科院分区：
文献类型：
--
作者：
Holmes,EH
有证据表明，β1 → 3 N-乙酰氨基葡萄糖转移酶的激活是导致人结肠腺癌中大量乳糖系列肿瘤相关抗原积累的原因。1型和2型核心链衍生物的表达表征人结肠腺癌，而正常成人结肠上皮细胞仅表达可检测量的1型链衍生物。研究了正常结肠粘膜和人结肠腺癌科洛205细胞的1型链乳糖系列碳水化合物结构特征的优先合成的基础。用α-乳白蛋白-琼脂糖柱层析法从科洛205细胞的TritonX-100溶解膜组分中分离出β1 → 3-和β1 → 4-半乳糖基转移酶，并研究了它们的性质。在0.1%Triton CF-54存在下，β1 → 3-连接的半乳糖向受体Lc 3的最佳转移发生在Triton X-100提供75%的最大活性的情况下。该酶在6.5至7.5的宽pH范围内具有活性，并且对Mn 2+具有接近绝对的需求。测定了供体UDP半乳糖和受体Lc 3的Km值分别为48和13 μm。与此相反，β1 → 4半乳糖基转移酶需要牛磺脱氧胆酸才能达到最大活性，并且在相同的测定条件下，发现Lc 3的Km比β1 → 3特异性酶高20倍。对SW 403和科洛205腺癌细胞富含高尔基体的膜组分中发现的膜结合β1 → 3-和β1 → 4半乳糖基转移酶的研究表明，在与体内乳糖系列核心链生物合成相似的条件下，优先合成1型链结构。结果表明，β1 → 3半乳糖基转移酶对受体Lc 3的高亲和力和膜的组织特征导致了1型链结构的优先合成。
Evidence indicates that activation of a β1 → 3N-acetylglucosaminyltransferase is responsible for accumulation of large quantities of lacto-series tumor-associated antigens in human colonic adenocarcinomas. Expression of type 1 and 2 core chain derivatives characterize human colonic adenocarcinomas, whereas normal adult colonic epithelial cells express detectable quantities of only type 1 chain derivatives. The basis for preferential synthesis of type 1 chain lacto-series carbohydrate structures characteristic of normal colonic mucosa and human colonic adenocarcinoma Colo 205 cells has been studied. The β1 → 3- and β1 → 4galactosyltransferase enzymes associated with synthesis of type 1 and 2 core chain structures, respectively, have been separated from a Triton X-100 solubilized membrane fraction of Colo 205 cells by chromatography on an α-lactalbumin-Sepharose column and their properties studied. Optimal transfer of β1 → 3-linked galactose to acceptor Lc3occurred in the presence of 0.1% Triton CF-54 with Triton X-100 providing 75% of maximal activity. The enzyme was active over a broad pH range from 6.5 to 7.5 and had a near absolute requirement for Mn2+. TheKmvalues for donor UDPgalactose and acceptor Lc3were determined to be 48 and 13 μm, respectively. In contrast, the β1 → 4galactosyltransferase required taurodeoxycholate for maximal activity and theKmfor Lc3was found to be 20-fold higher than that for the β1 → 3-specific enzyme under the same assay conditions. Studies with membrane-bound β1 → 3- and β1 → 4galactosyltransferases as found in Golgi-rich membrane fractions of SW403 and Colo 205 adenocarcinoma cells showed that preferential synthesis of type 1 chain structures occurs under conditions similar to thosein vivofor biosynthesis of lacto-series core chains. The results suggest that both the higher affinity of the β1 → 3galactosyl-transferase for acceptor Lc3and the membrane organizational features result in preferential synthesis of type 1 chain structures.