Specificity of β1,4-galactosyltransferase inhibition by 2-naphthyl 2-butanamido-2-deoxy-1-thio-β-D-glucopyranoside
Specificity of β1,4-galactosyltransferase inhibition by 2-naphthyl 2-butanamido-2-deoxy-1-thio-β-D-glucopyranoside
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DOI：
10.1007/s10719-010-9312-3
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发表时间：
2010-10-01
影响因子：
3
通讯作者：
Brockhausen, Inka
中科院分区：
文献类型：
--
作者：
Gao, Yin;Lazar, Carmen;Brockhausen, Inka
半乳糖基转移酶（GalT）抑制剂具有减少分泌的和细胞表面结合的糖蛋白上的粘附性碳水化合物的量的潜力。我们最近发现了一种有效的β 4GalT抑制剂，2-萘基2-丁酰胺基-2-脱氧-1-硫代-β-D-吡喃葡萄糖苷（化合物612）。在这项工作中，我们已经测试了化合物612的抑制特异性，并检查了其对GalT的影响，以及对不同细胞系匀浆中的GlcNAc-和GalNAc-转移酶，以及对重组糖基转移酶的影响。发现化合物612是β 4GalT的特异性抑制剂。重组人β 3 GalT 5也作用于GlcNAc-R底物，其特异性揭示了与牛乳β 4 GalT的相似之处。然而，612是一种不良的底物，而不是β 3GalT 5的抑制剂。为了进一步确定负责612的抑制性质的具体结构，我们合成了在糖苷键中含有氮的（2-萘基）-2-丁酰胺基-2-脱氧-β-D-吡喃葡萄糖胺（化合物629），并将其与作为底物和抑制剂的GlcNAc的其他萘基和喹啉基衍生物进行比较。化合物629是β 4GalT和β 3GalT 5的底物。这表明612的性质，而不是单独的萘基环的存在是其抑制作用的原因。结果表明，612在特异性阻断2型链的合成以及因此与2型链连接的表位方面是有用的。此外，612有效抑制细胞匀浆中的β 4GalT，因此允许在β 4GalT存在下测定β 3GalT活性。
Inhibitors of Galactosyltransferase (GalT) have the potential of reducing the amounts of adhesive carbohydrates on secreted and cell surface-bound glycoproteins. We recently found a potent inhibitor of beta 4GalT, 2-naphthyl 2-butanamido-2-deoxy-1-thio-beta-D-glucopyranoside (compound 612). In this work, we have tested compound 612 for the specificity of its inhibition and examined its effect on GalT, and on GlcNAc- and GalNAc-transferases in homogenates of different cell lines, as well as on recombinant glycosyltransferases. Compound 612 was found to be a specific inhibitor of beta 4GalT. The specificity of recombinant human beta 3GalT5 that also acts on GlcNAc-R substrates, revealed similarities to bovine milk beta 4GalT. However, 612 was a poor substrate and not an inhibitor for beta 3GalT5. To further determine the specific structures responsible for the inhibitory property of 612, we synthesized (2-naphthyl)-2-butanamido-2-deoxy-beta-D-glucopyranosylamine (compound 629) containing nitrogen in the glycosidic linkage, and compared it to other naphthyl and quinolinyl derivatives of GlcNAc as substrates and inhibitors. Compound 629 was a substrate for both beta 4GalT and beta 3GalT5. This suggests that properties of 612 other than the presence of the naphthyl ring alone were responsible for its inhibitory action. The results suggest a usefulness of 612 in specifically blocking the synthesis of type 2 chains and thus epitopes attached to type 2 chains. In addition, 612 potently inhibits beta 4GalT in cell homogenates and thus allows assaying beta 3GalT activity in the presence of beta 4GalT.