Detection of protein subunits of ferritin in situ in cells by immunofluorescence.
Detection of protein subunits of ferritin in situ in cells by immunofluorescence.
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通过免疫荧光原位检测细胞内铁蛋白的蛋白质亚基。
DOI：
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发表时间：
1974
影响因子：
6
通讯作者：
G. Richter
中科院分区：
文献类型：
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作者：
J. C. Lee;S. S. Lee;K. Schlesinger;G. Richter
兔抗大鼠肝铁蛋白蛋白亚基的抗血清含有沉淀亚基的抗体（IgG）和沉淀未解离铁蛋白和脱铁铁蛋白的其他抗体（IgG）。通过重复加入铁蛋白从免疫血清的IgG级分中去除后者抗体，留下特异性沉淀亚基的抗体。使用这些亚基特异性抗体，我们已经证明了亚基阳性位点的存在下，在细胞中的免疫荧光。亚基阳性位点在铁负荷的大鼠中表现得最好。这些位点弥漫性分布于大鼠肝脏中肝细胞和枯否细胞的细胞质以及大鼠肝脏和心脏中巨噬细胞和成纤维细胞的细胞质中。利用铁蛋白抗体，证明了铁蛋白存在于同种细胞中。虽然，通过免疫荧光，铁蛋白阳性和亚基阳性位点的细胞内定位是相似的，铁蛋白阳性免疫荧光是最强烈的普鲁士蓝阳性细胞质颗粒，其中高浓度的铁蛋白被推定为存在的基础上，电子显微镜研究。我们的发现可以解释为在所研究的几种细胞的细胞质中存在未缔合的亚基或亚基片段。也有可能这些细胞中部分组装的铁蛋白或脱铁铁蛋白分子与亚基特异性抗体反应。亚基特异性抗体可能有助于在细胞精细结构水平上定位铁蛋白分子的组装位点并阐明铁蛋白的生物合成。
Antisera raised in rabbits against protein subunits of rat liver ferritin contain antibodies (IgG) that precipitate subunits and other antibodies (IgG) that precipitate undissociated ferritin and apoferritin. Removal of the latter antibodies from IgG fractions of immune sera by repeated addition of ferritin leaves antibodies that specifically precipitate subunits. Using these subunit-specific antibodies, we have demonstrated the presence of subunit-positive sites in cells by immunofluorescence. Subunit-positive sites were best demonstrated in rats that had been loaded with iron. These sites were diffusely spread through the cytoplasm of hepatocytes and Kupffer cells in rat livers and of macrophages and fibroblasts in rat livers and hearts. With antibodies to ferritin, the presence of ferritin was demonstrated in the same kinds of cells. Although, by immunofluorescence, the intracellular localization of ferritin-positive and subunit-positive sites was similar, ferritin-positive immunofluorescence was most intense in Prussian blue-positive cytoplasmic granules in which high concentrations of ferritin were presumed to be present on the basis of electron microscopic studies. Our findings can be interpreted to indicate either the presence of unassociated subunits or of fragments of subunits in the cytoplasm of the several kinds of cells studied. It is also possible that partly assembled molecules of ferritin or apoferritin in these cells reacted with subunit-specific antibodies. Subunit-specific antibodies may be useful for localizing sites of assembly of ferritin molecules at the level of cell fine structure and for elucidation of the biosynthesis of ferritin.