Sanquin Research, Amsterdam, The Netherlands.
Mol Immunol. 2010 Apr;47(7-8):1592-4. doi: 10.1016/j.molimm.2010.02.021. Epub 2010 Mar 17.
Human IgG4 antibodies are dynamic molecules that in vivo exchange half-molecules to become bispecific antibodies. Here we show that IgG4 antibodies and IgG4 Fc fragments similarly exchange resulting in hybrid antibodies (a single Fab+Fc) with a molecular weight of ca. 100kDa. These antibodies can be separated from IgG4 and IgG4 Fc using size-exclusion chromatography and non-reducing SDS-PAGE. This method does not rely on a cross-linking immunoassay with its potential for false-positive results due to aggregation and it unambiguously demonstrates that the 'Fab-arm' exchange process depends entirely on the Fc part (hinge+CH2+CH3).
人 IgG4 抗体是动态分子，在体内交换半分子成为双特异性抗体。在这里，我们表明 IgG4 抗体和 IgG4 Fc 片段也同样交换，导致产生分子量约为 100kDa 的混合抗体（单个 Fab+Fc）。这些抗体可以使用排阻层析和非还原 SDS-PAGE 从 IgG4 和 IgG4 Fc 中分离出来。这种方法不依赖于交联免疫测定法，因为其可能由于聚集而产生假阳性结果，并且它明确地表明，'Fab 臂'交换过程完全取决于 Fc 部分（铰链+CH2+CH3）。
