Specific binding of human alpha interferon to a high affinity cell surface binding site on bovine kidney cells.
Specific binding of human alpha interferon to a high affinity cell surface binding site on bovine kidney cells.
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人α干扰素与牛肾细胞上高亲和力细胞表面结合位点的特异性结合。
DOI：
10.1016/s0021-9258(18)34579-4
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
H. Arnheiter
中科院分区：
文献类型：
--
作者：
K. Zoon;D. zur Nedden;H. Arnheiter
用125 I-标记的博尔顿和亨特试剂放射性标记从Namalwa细胞获得的病毒诱导的人α干扰素（HuIFN-α），并纯化至比活性为2 × 10（8）单位/mg蛋白质，比活性为4-12 microCi/mg蛋白质。在4 ℃下检测该125 I-IFN与牛肾细胞的结合。结合数据的Scatchard分析表明存在650个结合位点/细胞，配体结合的表观Kd为6 × 10（-11）M。胰蛋白酶或酸处理与125 I-IFN结合的细胞导致释放大于或等于77%的放射性，表明大部分放射性标记物质与细胞表面结合。抗人白细胞IFN的抗体而非抗人成纤维细胞IFN的抗体抑制放射性标记的IFN与细胞的结合。125 I-IFN的结合不被75倍摩尔过量的小鼠IFN抑制，但被200倍摩尔过量的人β（成纤维细胞）IFN抑制30%。这些数据与这些IFN对牛肾细胞的较低生物活性相一致。几种大肠杆菌衍生的HuIFN-α抑制放射性标记的IFN的结合达到与天然HuIFN-α相同的程度，但是HuIFN-α 1的四个片段，一种大肠杆菌衍生的HuIFN-α抑制放射性标记的IFN的结合。大肠杆菌衍生的86个氨基酸的NH 2-末端片段以及3种不同的合成的140、56或46个氨基酸的羧基末端片段不抑制结合。
Virus-induced human alpha interferon (HuIFN-alpha) derived from Namalwa cells and purified to a specific activity of 2 X 10(8) units/mg of protein was radiolabeled with 125I-labeled Bolton and Hunter reagent to a specific activity of 4-12 microCi/micrograms of protein. The binding of this 125I-IFN to bovine kidney cells was examined at 4 degrees C. Scatchard analysis of the binding data indicate the presence of 650 binding sites/cell and binding of the ligand with an apparent Kd of 6 X 10(-11) M. Trypsin or acid treatment of cells to which 125I-IFN was bound resulted in the release of greater than or equal to 77% of the radioactivity, indicating a majority of radiolabeled material was bound to the cell surface. Antibodies against human leukocyte IFN but not antibodies against human fibroblast IFN inhibited the binding of radiolabeled IFN to the cells. The binding of 125I-IFN was not inhibited by a 75-fold molar excess of mouse IFN but was inhibited 30% by a 200-fold molar excess of human beta (fibroblast) IFN. These data are compatible with the Lower biological activities of these IFNs on bovine kidney cells. Several Escherichia coli derived HuIFN-alpha s inhibited the binding of the radiolabeled IFN to the same extent as native HuIFN-alpha s, but four fragments of HuIFN-alpha 1, an E. coli-derived 86 amino acid NH2-terminal fragment as well as 3 different synthetic carboxy-terminal fragments of 140, 56, or 46 amino acids did not inhibit binding.