A New Ligand for Immunoglobulin G Subdomains by Screening of a Synthetic Peptide Library
A New Ligand for Immunoglobulin G Subdomains by Screening of a Synthetic Peptide Library
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DOI：
10.1002/cbic.200400368
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发表时间：
2005-07
期刊：
影响因子：
3.2
通讯作者：
A. Verdoliva;D. Marasco;A. de Capua;A. Saporito;P. Bellofiore;V. Manfredi;R. Fattorusso;C. Pedone-C.-Ped
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文献类型：
--
作者：
A. Verdoliva;D. Marasco;A. de Capua;A. Saporito;P. Bellofiore;V. Manfredi;R. Fattorusso;C. Pedone-C.-Ped
通过筛选通式（NH2-Cys1-X2-X3-X4）2-Lys-Gly-OH的合成肽库，选择二硫键环肽（其中X2-X3-X4是三肽Phe-His-His）作为免疫球蛋白G（IgG）的配体。经过初步色谱表征后，该肽已被证明可用作新的亲和配体，用于从生物液体中纯化多克隆和单克隆抗体，回收率高达 90%（90% 纯度）。该配体能够结合包含来自不同抗体同种型的 Fab 和 Fc 的抗体片段，这一事实表明存在至少两个不同的抗体结合位点。虽然 Fab 上的识别位点未知，但与 Fc 的比较结合研究，以及该肽（称为 Fc 受体模拟物，FcRM）与人类 FcγRIII 受体区域的惊人相似性，强烈表明该肽可以识别下铰链区的一段短氨基酸，这在自身免疫性疾病的触发中发挥着关键作用。独特的性质使配体对于抗体片段的纯化和作为 Fc 受体拮抗剂生成的先导物具有吸引力。
By screening a synthetic peptide library of general formula (NH2‐Cys1‐X2‐X3‐X4)2‐Lys‐Gly‐OH, a disulfide‐bridged cyclic peptide, where X2‐X3‐X4 is the tripeptide Phe‐His‐His, has been selected as a ligand for immunoglobulin G (IgG). The peptide, after a preliminary chromatographic characterization, has proved useful as a new affinity ligand for the purification of polyclonal as well as monoclonal antibodies from biological fluids, with recovery yields of up to 90 % (90 % purity). The ligand is able to bind antibody fragments containing both Fab and Fc from different antibody isotypes, a fact suggesting the presence of at least two different antibody‐binding sites. While the recognition site on Fab is unknown, comparative binding studies with Fc, in association with the striking similarities of the peptide (named Fc‐receptor mimetic, FcRM) with a region of the human FcγRIII receptor, strongly indicate that the peptide could recognize a short amino acid stretch of the lower hinge region, which has a key role in autoimmune disease triggering. The unique properties make the ligand attractive for both the purification of antibody fragments and as a lead for the generation of Fc‐receptor antagonists.