Ligand binding by murine IgM antibodies: intramolecular heterogeneity exists in certain, but not all, cases.
Ligand binding by murine IgM antibodies: intramolecular heterogeneity exists in certain, but not all, cases.
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鼠 IgM 抗体的配体结合：在某些但并非全部情况下存在分子内异质性。
DOI：
10.1016/0161-5890(88)90094-6
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发表时间：
1988
影响因子：
3.6
通讯作者：
Clem,LW
中科院分区：
文献类型：
--
作者：
Pascual,D;Clem,LW
通过平衡透析分析了8种杂交瘤衍生的鼠抗DNP IgM（IgM）抗体的配体结合特性。这些蛋白质中有4个显示出预期的约10价和相对较低的亲和力（约2.2 × 105M−1）。其余四种蛋白质的化合价远低于10（108），亲和力相对较高（> 106M−1）。当这些蛋白质进行两个循环的冻干时，观察到前一组的那些蛋白质仍显示出每个分子约10个位点，具有与相应未处理分子相似的均匀亲和力。然而，观察到后一组中的分子（化合价为（108））在冻干后仅表现出5至6个结合位点，亲和力没有变化。当来自每个IgM（κ）蛋白的还原亚基经受胰蛋白酶消化时，在Fabμ片段的产量方面观察到两种不同的模式。最初表现出约10个结合位点的每种蛋白质产生>90%的预期Fabμ片段。相比之下，显示出Fab μ 8结合位点的每种蛋白质仅产生约50%的预期Fabμ片段。总之，这些结果表明存在至少两种不同形式的鼠IgM分子，具有约10个同质、相对稳定位点的那些和仅具有约10个同质、相对稳定位点的那些。五个稳定的地点。这表明，这些分子内的功能差异可能是由于分子内的构象差异。
The ligand binding properties of eight hybridoma-derived murine anti-DNP IgM(ϰ) antibodies were analysed by equilibrium dialysis. Four of these proteins exhibited the expected valances of ~ 10 and relatively low affinities (⩽2.2 × 105M−1). The remaining four proteins exhibited valences of considerably less than 10 (⩽8) and relatively high affinities (> 106M−1). When these proteins were subjected to two cycles of lyophilization, those of the former group were observed to still exhibit ~10 sites per molecule with homogeneous affinities similar to those of the respective untreated molecules. However, molecules in the latter group (valences of (⩽ 8) were observed to exhibit only five to six binding sites subsequent to lyophilization with no changes in affinities. When the reductive subunits from each of the IgM(κ) proteins were subjected to trypsinization, two different patterns were observed in terms of the yields of Fabμ fragments. Each of the proteins originally exhibiting ~10 binding sites yielded >90% of the expected Fabμ fragments. In contrast each of the proteins exhibiting ⩽8 binding sites yielded only ~50% of the expected Fabμ fragments. Collectively these results indicate the existence of at least two different forms of murine IgM molecules, those with ~ 10 homogeneous, relatively stable sites and those with only approx. five stable sites. It is suggested that these intramolecular functional differences may be attributable to intramolecular conformational differences.