Intermolecular interactions and conformation of antibody dimers present in IgG1 biopharmaceuticals
Intermolecular interactions and conformation of antibody dimers present in IgG1 biopharmaceuticals
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DOI：
10.1093/jb/mvt095
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发表时间：
2014-01-01
影响因子：
2.7
通讯作者：
Arisaka, Fumio
中科院分区：
文献类型：
--
作者：
Iwura, Takafumi;Fukuda, Jun;Arisaka, Fumio
研究了Palivizumab单克隆抗体（IgG1）二聚体中的分子间相互作用和构象，以阐明二聚体抗体的物理和化学性质。帕利珠单抗溶液含有类似于1%二聚体和99%单体。二聚体采用粒径排除色谱法分离，并采用超离心沉降速度（AUC-SV）等多种方法进行分析。AUC-SV在十二烷基硫酸钠的存在下表明，大约一半的二聚体部分是非共价结合的，而另一半则是通过共价键二聚的。二硫化物键和二酪氨酸的形成可能参与了共价二聚化。Lys-C和质谱分析表明，分离的二聚体是由F-ab-F-c或F-ab-F-ab相互作用形成的，而没有发现F-c-F-c相互作用。因此二聚化很可能主要通过F-ab区发生。关于二聚体的构象，二级和三级结构与单体的构象几乎相同。此外，二聚体和单体的热稳定性也非常相似。
Intermolecular interactions and conformation in dimer species of Palivizumab, a monoclonal antibody (IgG1), were investigated to elucidate the physical and chemical properties of the dimerized antibody. Palivizumab solution contains similar to 1% dimer and 99% monomer. The dimer species was isolated by size-exclusion chromatography and analysed by a number of methods including analytical ultracentrifugation-sedimantetion velocity (AUC-SV). AUC-SV in the presence of sodium dodecyl sulphate indicated that approximately half of the dimer fraction was non-covalently associated, whereas the other half was dimerized by covalent bond. Disulphide bond and dityrosine formation were likely to be involved in the covalent dimerization. Limited proteolysis of the isolated dimer by Lys-C and mass spectrometry for the resultant products indicated that the dimer species were formed by F-ab-F-c or F-ab-F-ab interactions, whereas F-c-F-c interactions were not found. It is thus likely that the dimerization occurs mainly via the F-ab region. With regard to the conformation of the dimer species, the secondary and tertiary structures were shown to be almost identical to those of the monomer. Furthermore, the thermal stability turned out also to be very similar between the dimer and monomer.