在UDP-Gal/UDP-GalNAc 4-epimerase缺陷突变体中,O相关的糖化和LDL受体表达的可逆缺陷
Cell
|March 14, 1986
概括
缺乏UDP-银河糖和UDP-N-乙银河胺4-表酶的仓鼠细胞突变体 (ldld) 不能合成必需的糖. 补充银河糖和GalNAc可以纠正所有糖化缺陷,包括LDL受体活性.
科学领域:
- 生物化学 生物化学
- 细胞生物学 细胞生物学
- 遗传学 是一个遗传学.
背景情况:
- 此前已经分离出了一种不寻常的仓鼠细胞突变 (ldld),表现出缺陷的LDL受体活性.
- 这种缺陷与细胞在正常培养条件下无法表达LDL受体活性有关.
研究的目的:
- 为了确定 ldlD 细胞中特定的酶缺陷,负责它们的糖化缺陷.
- 阐明UDP-银糖和UDP-N-乙银胺 (GalNAc) 在细胞糖化和LDL受体功能中的作用.
主要方法:
- 生物化学测试用于测量LDLD细胞中的酶活性.
- 用不同介质补充剂 (血清,葡萄糖,银河糖,GalNAc) 进行细胞培养实验.
- 在合成的葡萄糖脂和葡萄糖蛋白中分析糖化模式.
主要成果:
- ldlD细胞缺乏UDP-银糖和UDP-N-乙酸银胺 (GalNAc) 4-epimerase.
- 这种缺陷阻止了基于葡萄糖的介质中UDP-银糖和UDP-GalNAc的正常合成,导致缺陷的葡萄糖脂和葡萄糖蛋白合成.
- 外源性银河糖和GalNAc完全纠正了所有观察到的表型异常,包括LDL受体表达.
结论:
- 4 - 胺酶缺乏是LDLD细胞中糖化缺陷的唯一原因.
- O链的碳水化合物链对于LDL受体的稳定性至关重要.
- ldlD细胞为研究含有银河糖和GalNAc的生物分子提供了有价值的模型.
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