Dooley Helen, Flajnik Martin F, Porter Andrew J
Department of Molecular and Cell Biology, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, Scotland, UK.
Mol Immunol. 2003 Sep;40(1):25-33. doi: 10.1016/s0161-5890(03)00084-1.
The novel immunoglobulin isotype novel antigen receptor (IgNAR) is found in cartilaginous fish and is composed of a heavy-chain homodimer that does not associate with light chains. The variable regions of IgNAR function as independent domains similar to those found in the heavy-chain immunoglobulins of Camelids. Here, we describe the successful cloning and generation of a phage-displayed, single-domain library based upon the variable domain of IgNAR. Selection of such a library generated from nurse sharks (Ginglymostoma cirratum) immunized with the model antigen hen egg-white lysozyme (HEL) enabled the successful isolation of intact antigen-specific binders matured in vivo. The selected variable domains were shown to be functionally expressed in Escherichia coli, extremely stable, and bind to antigen specifically with an affinity in the nanomolar range. This approach can therefore be considered as an alternative route for the isolation of minimal antigen-binding fragments with favorable characteristics.
新型免疫球蛋白同种型新型抗原受体（IgNAR）存在于软骨鱼类中，由不与轻链结合的重链同型二聚体组成。IgNAR的可变区作为独立结构域发挥作用，类似于在骆驼科动物重链免疫球蛋白中发现的结构域。在此，我们描述了基于IgNAR可变域成功克隆和构建噬菌体展示单结构域文库的过程。用模型抗原鸡卵清溶菌酶（HEL）免疫护士鲨（Ginglymostoma cirratum）产生的此类文库的筛选，使得能够成功分离出在体内成熟的完整抗原特异性结合物。所选可变域在大肠杆菌中显示出功能性表达，极其稳定，并以纳摩尔范围内的亲和力特异性结合抗原。因此，这种方法可被视为分离具有良好特性的最小抗原结合片段的替代途径。
