1,4-Dideoxy-1,4-imino-D-mannitol inhibits glycoprotein processing and mannosidase.
1,4-Dideoxy-1,4-imino-D-mannitol inhibits glycoprotein processing and mannosidase.
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DOI：
10.1016/0003-9861(85)90771-4
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发表时间：
1985-11
影响因子：
3.9
通讯作者：
G. Palamarczyk;M. Mitchell;P. Smith;G. Fleet;A. Elbein
中科院分区：
文献类型：
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作者：
G. Palamarczyk;M. Mitchell;P. Smith;G. Fleet;A. Elbein
1，4-二脱氧-1，4-亚氨基-d-甘露醇（DIM）是从苄基-α-d-吡喃甘露糖苷化学合成的[Fleetet al（1984）J. Chem. Soc. Chem. Commun.，1240-1241]，并在体外作为各种α-甘露糖苷酶的抑制剂和在细胞培养物中作为糖蛋白加工的抑制剂进行了测试。DIM被证明是刀豆α-甘露糖苷酶的有效抑制剂，50%的抑制需要25至50 ng/ml的抑制剂。它也抑制溶酶体α-甘露糖苷酶，但在这种情况下，50%的抑制需要约1至2 μg/ml。当对硝基苯基-α-d-吡喃甘露糖苷为底物时，两种情况下的抑制作用均为竞争型。在较高的pH值下，抑制作用更好，这表明当环中的氮处于未质子化形式时，DIM更有效。此外，大鼠肝脏加工甘露糖苷酶I也被DIM抑制，通过从[3 H]甘露糖标记的Man 9 GlcNAc释放[3 H]甘露糖来测量。在流感病毒感染的MDCK细胞中检查糖蛋白加工。将感染的细胞在各种浓度的DIM中孵育并用[2- 3 H]甘露糖标记。用链霉蛋白酶消化病毒和细胞沉淀，并通过Bio-Gel P-4柱上的凝胶过滤分离糖肽。然后用内切氨基葡萄糖苷酶H（Endo H）处理糖肽，并在Bio-Gel柱上进行再层析，以区分复合物和高甘露糖结构。随着培养基中DIM浓度的升高，越来越多的[3 H]甘露糖被掺入高甘露糖寡糖中，复合物链中的放射性越来越少。通过凝胶过滤、HPLC和α-甘露糖苷酶消化测定，DIM诱导的大多数Endo H释放的寡糖具有Man 9 GlcNAc结构。因此，DIM似乎也抑制细胞培养物中的甘露糖苷酶I。然而，约15%的Endo H释放的寡糖似乎是寡糖的混合类型，表明DIM也可能抑制甘露糖苷酶II。
1,4-Dideoxy-1,4-imino-d-mannitol (DIM) was synthesized chemically from benzyl-α-d-mannopyranoside [Fleetet al(1984)J. Chem. Soc. Chem. Commun., 1240–1241], and was testedin vitroas an inhibitor of various α-mannosidases and in cell culture as an inhibitor of glycoprotein processing. DIM proved to be an effective inhibitor of jack bean α-mannosidase, with 50% inhibition requiring 25 to 50 ng/ml inhibitor. It also inhibited lysosomal α-mannosidase, but in this case 50% inhibition required about 1 to 2 μg/ml. In both cases, the inhibition was of the competitive type whenp-nitrophenyl-α-d-mannopyranoside was used as the substrate. The inhibition was better at higher pH values, suggesting that DIM was more effective when the nitrogen in the ring was in the unprotonated form. In addition, rat liver processing mannosidase I was also inhibited by DIM as measured by the release of [3H]mannose from [3H]mannose-labeled Man9GlcNAc. Glycoprotein processing was examined in influenza virus-infected MDCK cells. Infected cells were incubated in various concentrations of DIM and labeled with [2-3H]mannose. Viral and cell pellets were digested with Pronase and glycopeptides were isolated by gel filtration on columns of Bio-Gel P-4. The glycopeptides were then treated with endoglucosaminidase H (Endo H) and rechromatographed on the Bio-Gel column in order to distinguish complex from high-mannose structures. As the DIM concentration in the medium was raised, more and more of the [3H]mannose was incorporated into high-mannose oligosaccharides, and less and less radioactivity was in the complex chains. Most of the Endo H-released oligosaccharides induced by DIM were of the Man9GlcNAc structure, as determined by gel filtration, HPLC, and digestion by α-mannosidase. Thus, DIM also appears to inhibit mannosidase I in cell culture. However, about 15% of the Endo H-released oligosaccharides appear to be hybrid types of oligosaccharides, suggesting that DIM may also inhibit mannosidase II.