Physicochemical and immunohistological studies of a sulfobromophthalein- and bilirubin-binding protein from rat liver plasma membranes.
Physicochemical and immunohistological studies of a sulfobromophthalein- and bilirubin-binding protein from rat liver plasma membranes.
复制标题
来自大鼠肝质膜的磺溴酞和胆红素结合蛋白的物理化学和免疫组织学研究。
DOI：
10.1172/jci110935
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
Berk,PD
中科院分区：
文献类型：
--
作者：
Stremmel,W;Gerber,MA;Glezerov,V;Thung,SN;Kochwa,S;Berk,PD
采用亲和层析法从Triton x -100溶解大鼠肝质膜中分别分离出对胆红素和BSP具有高亲和性的两种蛋白。从两个亲和柱洗脱的蛋白在十二烷基硫酸钠(SDS)-聚丙烯酰胺凝胶电泳上以约55,000 D的单带迁移，在Sephadex G-75上与[14C]胆红素和[35S]BSP共层。在没有还原或SDS的梯度凝胶上，或在Sephadex G-150上，天然bsp结合蛋白的分子质量估计约为100,000 D。在与SDS孵育后，观察到额外的Sephadex G-150分子质量峰值为56,000 D。100000 - d和56000 - d G-150峰均用[35S]BSP共色谱。天然蛋白的等电点为3.5，染色为周期性酸-希夫而非苏丹黑，每mol蛋白质含有4 mol唾液酸。BSP结合蛋白的兔抗体与BSP-和胆红素结合抗原同源，抑制[14C]胆红素和[35S]BSP结合，但不抑制[14C]油酸盐或[14C]牛磺酸胆酸盐与大鼠肝质膜的结合。免疫组织化学研究显示，抗原存在于大鼠肝细胞的所有表面域，但不存在于正常大鼠肝脏的其他细胞群。在其他器官中没有发现。这些数据与一种特定的肝细胞膜蛋白介导胆红素和BSP的肝细胞隔离的假设是一致的。图片
Affinity chromatography over bilirubinagarose and sulfobromophthalein (BSP)-agarose was used to isolate two proteins, with high affinities for bilirubin and BSP, respectively, from Triton X-100-solubilized rat liver plasma membranes. The protein eluted from either affinity column migrated as a single band of approximately 55,000 D on sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, and either protein cochromatographed with both [14C]bilirubin and [35S]BSP on Sephadex G-75. On gradient gels without reduction or SDS, or on Sephadex G-150, the native BSP-binding protein had an estimated molecular mass of approximately 100,000 D. After incubation with SDS, an additional Sephadex G-150 peak of molecular mass of 56,000 D was observed. Both, the 100,000- and 56,000-D G-150 peaks cochromatographed with [35S]BSP. The native protein had an isoelectric point of 3.5, stained with periodic acid-Schiff but not Sudan black, and contained 4 mol of sialic acid per mol of protein. A rabbit antibody to the BSP-binding protein gave a line of identity with both the BSP- and bilirubin-binding antigens, and inhibited the binding of [14C]bilirubin and [35S]BSP, but not [14C]oleate or [14C]taurocholate, to rat liver plasma membranes. Immunohistochemical studies revealed the presence of the antigen on all surface domains of rat hepatocytes, but not on other cell populations from normal rat liver. It was not found in other organs. These data are compatible with the hypothesis that a specific liver cell plasma membrane protein mediates the hepatocytic sequestration of bilirubin and BSP.Images