Pharma Technical Development Europe (Biologics) Analytics, F. Hoffmann-La Roche Ltd., 4070, Basel, Switzerland.
Pharm Res. 2012 Aug;29(8):2047-59. doi: 10.1007/s11095-012-0732-6. Epub 2012 Apr 5.
To investigate structure and function of different monoclonal antibody (MAb) dimers.
MAb dimers were induced by process-related, low pH and UV light stress. Dimers were isolated and purified by chromatography and extensively characterized by biochemical, structural and functional methods.
Highly purified dimer forms were obtained which enabled detailed characterization. Dimers induced by process stress were associated by a single non-covalent interaction site between two Fab domains in a characteristic "bone-like" structure observed in Transmission Electron Microscopy (TEM). These dimers showed reduced potency and antigen binding affinity. Low pH stress generated more stable but also non-covalently associated dimers without chemical alterations in a typical "closed" conformation according to TEM. These dimer species were more compact and more hydrophobic as dimers induced by process stress. They showed bioactivity and antigen binding affinity similar to the native monomer. Light-induced dimers, exhibiting various different conformations, were the most stable dimers with various chemical modifications leading to a broad range in size, charge and hydrophobicity. These dimers fully lost bioactivity and antigen binding affinity.
The use of highly purified MAb dimers and a panel of characterizations methods enabled to obtain a clear picture about molecular architecture and function of dimers.
研究不同单克隆抗体（MAb）二聚体的结构和功能。
通过过程相关的低 pH 值和紫外光应激诱导 MAb 二聚体。通过色谱法分离和纯化二聚体，并通过生化、结构和功能方法进行广泛表征。
获得了高度纯化的二聚体形式，从而能够进行详细的表征。过程应激诱导的二聚体通过 Fab 结构域之间的单个非共价相互作用位点缔合，在透射电子显微镜（TEM）中观察到特征性的“骨样”结构。这些二聚体显示出降低的效力和抗原结合亲和力。低 pH 值应激产生更稳定但也非共价缔合的二聚体，没有根据 TEM 观察到的化学变化呈典型的“关闭”构象。这些二聚体种类比过程应激诱导的二聚体更紧凑且更疏水。它们表现出与天然单体相似的生物活性和抗原结合亲和力。表现出各种不同构象的光诱导二聚体是最稳定的二聚体，具有各种化学修饰，导致大小、电荷和疏水性广泛变化。这些二聚体完全失去了生物活性和抗原结合亲和力。
使用高度纯化的 MAb 二聚体和一系列表征方法，能够清楚地了解二聚体的分子结构和功能。
