Kelm S, Schauer R
Biochemisches Institut der Universität zu Kiel.
Biol Chem Hoppe Seyler. 1988 Aug;369(8):693-704. doi: 10.1515/bchm3.1988.369.2.693.
Resident rat peritoneal macrophages express a galactose-recognizing system, which mediates binding and uptake of cells and glycoproteins exposing terminal galactose residues. Here we describe the identification, isolation, and characterization of the corresponding receptor molecule. Using photoaffinity labelling of adherent peritoneal macrophages with the 4-azido-6-125I-salicylic acid derivative of anti-freeze glycoprotein 8 followed by SDS-PAGE and autoradiography, we identified the receptor of these cells as a protein with an apparent molecular mass of 42 kDa. Furthermore, cell surface receptors were radioiodinated by an affinity-supported labelling technique using the conjugate of asialoorosomucoid and lactoperoxidase, followed by extraction and isolation by affinity chromatography. Finally, the native receptor was isolated and analysed. To estimate its binding activity in solutions, a suitable binding assay was developed, using the precipitation of receptor-ligand complex with polyethylene glycol to separate bound from unbound 125I-asialoorosomucoid, which was used as ligand. It is shown that the isolated receptor binds to galactose-exposing particles and distinguishes between sialidase-treated and -untreated erythrocytes, similar to peritoneal macrophages. The binding characteristics of the membrane-bound and the solubilized receptor are described in the following paper of Lee et al.
大鼠腹膜常驻巨噬细胞表达一种半乳糖识别系统，该系统介导暴露末端半乳糖残基的细胞和糖蛋白的结合与摄取。在此，我们描述了相应受体分子的鉴定、分离及特性。用抗冻糖蛋白8的4-叠氮基-6-¹²⁵I-水杨酸衍生物对贴壁腹膜巨噬细胞进行光亲和标记，随后进行SDS-PAGE和放射自显影，我们将这些细胞的受体鉴定为一种表观分子量为42 kDa的蛋白质。此外，利用去唾液酸血清类黏蛋白与乳过氧化物酶的偶联物，通过亲和支持标记技术对细胞表面受体进行放射性碘化，随后通过亲和层析进行提取和分离。最后，分离并分析了天然受体。为了评估其在溶液中的结合活性，开发了一种合适的结合测定法，即利用聚乙二醇沉淀受体-配体复合物，以分离结合态与游离态的¹²⁵I-去唾液酸血清类黏蛋白（用作配体）。结果表明，分离出的受体与暴露半乳糖的颗粒结合，并能区分经唾液酸酶处理和未处理的红细胞，这与腹膜巨噬细胞类似。膜结合受体和可溶性受体的结合特性在Lee等人的后续论文中进行了描述。
