Yoshitake Y, Nishikawa K
Department of Biochemistry, Kanazawa Medical University, Ishikawa, Japan.
Arch Biochem Biophys. 1988 Jun;263(2):437-46. doi: 10.1016/0003-9861(88)90656-x.
Four different monoclonal antibodies (MAbs) to human epidermal growth factor (hEGF) were obtained from mouse hybridoma cell lines. They were highly specific for hEGF and did not cross-react appreciably with mouse EGF. The immunoglobulin class of these MAbs was IgG1 or IgG2a. The apparent Kd values for hEGF of these MAbs ranged from 10(-10) to 10(-9) M. These MAbs all inhibited DNA synthesis in BALB/c3T3 cells stimulated by hEGF and 125I-labeled hEGF binding to the receptor of the cells. Reduction of hEGF with dithiothreitol decreased its reactivity with these MAbs, suggesting that they recognized the conformation of the hEGF molecule maintained by the three disulfide bonds. By competitive binding experiments with hEGF, these four MAbs were classified into three groups: two binding to an A domain of hEGF, one to a B domain, and one to a C domain and preventing the bindings of the other MAbs at the A and B domains. When a methionyl residue of hEGF was removed by its treatment with CNBr, the immunological reactivity of the C domain, but not the A or B domain, was destroyed in association with a decrease in the biological activity of the growth factor. These MAbs should be useful in studies on the structure-function relationship of hEGF.
从鼠杂交瘤细胞系中获得了四种针对人表皮生长因子（hEGF）的不同单克隆抗体（MAb）。它们对hEGF具有高度特异性，与小鼠表皮生长因子（mEGF）没有明显的交叉反应。这些单克隆抗体的免疫球蛋白类别为IgG1或IgG2a。这些单克隆抗体与hEGF的表观解离常数（Kd）值范围为10^(-10)至10^(-9) M。这些单克隆抗体均抑制hEGF刺激的BALB/c3T3细胞中的DNA合成以及125I标记的hEGF与细胞受体的结合。用二硫苏糖醇还原hEGF会降低其与这些单克隆抗体的反应性，这表明它们识别由三个二硫键维持的hEGF分子构象。通过与hEGF的竞争性结合实验，这四种单克隆抗体被分为三组：两种与hEGF的A结构域结合，一种与B结构域结合，一种与C结构域结合，并阻止其他单克隆抗体在A和B结构域的结合。当用溴化氰处理hEGF去除其甲硫氨酸残基时，C结构域的免疫反应性被破坏，而A或B结构域未被破坏，同时生长因子的生物学活性降低。这些单克隆抗体在hEGF的结构-功能关系研究中应具有重要作用。
