Proudfoot K A, Torrance C, Lawson A D, King D J
Celltech Ltd., Slough, United Kingdom.
Protein Expr Purif. 1992 Oct;3(5):368-73. doi: 10.1016/s1046-5928(05)80037-3.
Streptococcal protein G has been used extensively for the purification of antibodies using the interaction of the Fc region with protein G. Many antibodies also interact with protein G through a low-affinity binding site for the Fab region. The exploitation of this low-affinity interaction for the purification of Fab' fragments is described here. Chimeric mouse-human B72.3 Fab' and F(ab')2 fragments were expressed by CHO cells and purified from CHO cell supernatant using protein G-Sepharose. Since chimeric B72.3 Fab' bound weakly to the protein G-Sepharose it could be separated from F(ab')2 and eluted with a pH 7 wash whereas B72.3 F(ab')2 required elution at pH 2. Both Fab' and F(ab')2 were recovered with full immunoreactivity and could be further purified using gel-filtration chromatography to greater than 99% purity. This method allows the simple purification of directly expressed Fab' or F(ab')2 fragments from CHO cell supernatant.
链球菌蛋白G已被广泛用于利用Fc区域与蛋白G的相互作用来纯化抗体。许多抗体还通过Fab区域的低亲和力结合位点与蛋白G相互作用。本文描述了利用这种低亲和力相互作用来纯化Fab'片段的方法。嵌合的小鼠-人B72.3 Fab'和F(ab')2片段由CHO细胞表达，并使用蛋白G-琼脂糖从CHO细胞上清液中纯化。由于嵌合的B72.3 Fab'与蛋白G-琼脂糖的结合较弱，它可以与F(ab')2分离，并用pH 7的洗脱液洗脱，而B72.3 F(ab')2需要在pH 2下洗脱。Fab'和F(ab')2均以完全免疫反应性回收，并且可以使用凝胶过滤色谱进一步纯化至纯度大于99%。该方法允许从CHO细胞上清液中简单地纯化直接表达的Fab'或F(ab')2片段。
