Gong Yiyi, Zhang Lin, Li Jin, Feng Shan, Deng Haiteng
MOE Key Laboratory of Bioinformatics, School of Life Sciences and ‡Tsinghua University-Peking University Joint Center for Life Sciences, Tsinghua University , Beijing, China , 100084.
Bioconjug Chem. 2016 Jul 20;27(7):1569-73. doi: 10.1021/acs.bioconjchem.6b00170. Epub 2016 Jul 5.
Development of a peptide-based affinity matrix and detection reagent is important for biomedical research and the biopharmaceutical industry. In the present work, we designed and synthesized an immunoglobin G (IgG)-binding peptide ligand, Fc-III-4C. Fc-III-4C is composed of 15 residues, and the 4 cysteine residues form 2 disulfide bonds to generate a double cyclic structure. The binding affinity of the Fc-III-4C peptide toward human IgG was determined to be 2.45 nM (Kd), which is higher than that of IgG with Protein A/G (Pro-A/G). Importantly, the Fc-III-4C peptide displayed high affinity to various IgGs from different species. Fc-III-4C immobilized agarose beads exhibited high stability and reusability when compared with that of the Pro-A/G-immobilized beads. The conjugate of Fc-III-4C with FITC was demonstrated to be suitable for immunofluorescence detection of proteins expressed in cells. These results demonstrate that the Fc-III-4C peptide is a useful affinity ligand for antibody purification and as a protein detection reagent.
基于肽的亲和基质和检测试剂的开发对生物医学研究和生物制药行业至关重要。在本研究中，我们设计并合成了一种免疫球蛋白G（IgG）结合肽配体Fc-III-4C。Fc-III-4C由15个残基组成，4个半胱氨酸残基形成2个二硫键以产生双环结构。测定Fc-III-4C肽对人IgG的结合亲和力为2.45 nM（解离常数），高于IgG与蛋白A/G（Pro-A/G）的结合亲和力。重要的是，Fc-III-4C肽对来自不同物种的各种IgG表现出高亲和力。与Pro-A/G固定化珠相比，Fc-III-4C固定化琼脂糖珠表现出高稳定性和可重复使用性。Fc-III-4C与异硫氰酸荧光素（FITC）的缀合物被证明适用于细胞中表达的蛋白质的免疫荧光检测。这些结果表明，Fc-III-4C肽是用于抗体纯化和作为蛋白质检测试剂的有用亲和配体。
