Nilson B H, Lögdberg L, Kastern W, Björck L, Akerström B
Department of Medical and Physiological Chemistry, University of Lund, Sweden.
J Immunol Methods. 1993 Aug 26;164(1):33-40. doi: 10.1016/0022-1759(93)90273-a.
Protein L from the bacterial species Peptostreptococcus magnus binds specifically to the variable domain of Ig light chains, without interfering with the antigen-binding site. In this work a genetically engineered fragment of protein L, including four of the repeated Ig-binding repeat units, was employed for the purification of Ig from various sources. Thus, IgG, IgM, and IgA were purified from human and mouse serum in a single step using protein L-Sepharose affinity chromatography. Moreover, human and mouse monoclonal IgG, IgM, and IgA, and human IgG Fab fragments, as well as a mouse/human chimeric recombinant antibody, could be purified from cultures of hybridoma cells or antibody-producing bacterial cells, with protein L-Sepharose. This was also the case with a humanized mouse antibody, in which mouse hypervariable antigen-binding regions had been introduced into a protein L-binding kappa subtype III human IgG. These experiments demonstrate that it is possible to engineer antibodies and antibody fragments (Fab, Fv) with protein L-binding framework regions, which can then be utilized in a protein L-based purification protocol.
来自巨大消化链球菌的L蛋白可特异性结合Ig轻链可变区，而不干扰抗原结合位点。在本研究中，使用了L蛋白的一个基因工程片段，该片段包含四个重复的Ig结合重复单元，用于从各种来源纯化Ig。因此，利用L蛋白-琼脂糖亲和色谱法，可一步从人血清和小鼠血清中纯化出IgG、IgM和IgA。此外，人源和鼠源单克隆IgG、IgM和IgA、人IgG Fab片段以及鼠/人嵌合重组抗体，均可利用L蛋白-琼脂糖从杂交瘤细胞培养物或产生抗体的细菌细胞中纯化出来。人源化小鼠抗体也是如此，该抗体已将小鼠高变抗原结合区引入到一个与L蛋白结合的κ亚型III人IgG中。这些实验表明，有可能构建具有与L蛋白结合框架区的抗体和抗体片段（Fab、Fv），然后可将其用于基于L蛋白的纯化方案。
