Marlovits T C, Abrahamsberg C, Blaas D
Institute of Biochemistry, University of Vienna, Dr. Bohr Gasse 9/3, A-1030 Vienna, Austria.
J Biol Chem. 1998 Dec 11;273(50):33835-40. doi: 10.1074/jbc.273.50.33835.
Soluble human low density lipoprotein minireceptors with less than seven ligand binding repeats (as are present in the native membrane receptor) were expressed in Sf9 insect cells with a hexa-His tag fused to the C terminus. The recombinant truncated proteins were affinity purified from the tissue culture supernatants by Ni-NTA column chromatography. Minireceptors with more than two repeats bound to rabbit beta very low density lipoprotein and could thus be further purified by affinity chromatography. Binding and cell protection assays indicated that two ligand binding repeats are sufficient for attachment of minor group human rhinoviruses to immobilized receptors, whereas at least three ligand binding repeats are required to protect HeLa cells against viral infection.
具有少于七个配体结合重复序列（如天然膜受体中存在的那样）的可溶性人低密度脂蛋白微型受体在Sf9昆虫细胞中表达，其C末端融合有六组氨酸标签。重组截短蛋白通过Ni-NTA柱色谱从组织培养上清液中亲和纯化。具有两个以上重复序列的微型受体与兔β极低密度脂蛋白结合，因此可以通过亲和色谱进一步纯化。结合和细胞保护试验表明，两个配体结合重复序列足以使小群人鼻病毒附着于固定化受体，而至少需要三个配体结合重复序列才能保护HeLa细胞免受病毒感染。
