Kaetzel C S, Rao C K, Lamm M E
Biochem J. 1987 Jan 1;241(1):39-47. doi: 10.1042/bj2410039.
The purification of human placenta and rat liver protein disulphide-isomerase (PDI, EC 5.3.4.1) and the production of a panel of monoclonal antibodies against these proteins are described. The physical and enzymic properties of human PDI and rat PDI were similar; immunological characterization revealed the presence of unique, as well as shared, antigenic determinants. Although purified rat liver PDI was present as three forms differing slightly in Mr value, evidence was presented that the multiple forms represent proteolytic degradation products of a single 59,000-Mr species. Purified human PDI had an apparent Mr of 61,200. Two of the monoclonal antibodies against human PDI partially inactivated the enzyme, and one of these in indirect immunoprecipitation led to the precipitation of all glutathione:insulin transhydrogenase activity from a crude extract of human placenta. Results of immunofluorescence experiments with HT-29 human colon carcinoma cells were consistent with localization of PDI in the nuclear membrane and cell cytoplasm.
本文描述了人胎盘和大鼠肝脏蛋白二硫键异构酶（PDI，EC 5.3.4.1）的纯化过程以及针对这些蛋白质的一组单克隆抗体的制备。人PDI和大鼠PDI的物理和酶学性质相似；免疫特性分析显示存在独特的以及共有的抗原决定簇。尽管纯化的大鼠肝脏PDI以三种分子量略有不同的形式存在，但有证据表明这些多种形式代表单一59,000分子量物种的蛋白水解降解产物。纯化的人PDI的表观分子量为61,200。两种针对人PDI的单克隆抗体使该酶部分失活，其中一种在间接免疫沉淀中导致从人胎盘粗提物中沉淀出所有谷胱甘肽：胰岛素转氢酶活性。用HT-29人结肠癌细胞进行的免疫荧光实验结果与PDI定位于核膜和细胞质一致。
