Strategy of Fc-recognizable Peptide ligand design for oriented immobilization of antibody.
Strategy of Fc-recognizable Peptide ligand design for oriented immobilization of antibody.
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DOI：
10.1021/ac4029467
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发表时间：
2014-02
影响因子：
7.4
通讯作者：
C. Tsai;Siang-long Jheng;Wen-Yih Chen;R. Ruaan
中科院分区：
文献类型：
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作者：
C. Tsai;Siang-long Jheng;Wen-Yih Chen;R. Ruaan
提出了一种设计与抗体 Fc 区具有高亲和力的短链肽配体的新策略。靶向抗体是源自小鼠 IgG2a 的人前列腺特异性抗体 (PSA)。配体设计策略涉及两个主要部分：结合位点选择和肽配体设计。选择靠近抗体 Fc 区底部的暴露疏水斑块之一作为结合位点，该疏水斑块是通过萘和封端色氨酸的分子对接而鉴定的。在检查了结合位点周围的电荷分布后，根据可能的疏水和静电相互作用设计了各种肽配体。通过分子动力学（MD）模拟分析，发现肽配体RRGW具有高Fc结合亲和力。前两个残基（两个精氨酸）在肽与抗体 Fc 区之间的静电相互作用中发挥重要作用。第四个残基，色氨酸，提供 VDW 力；肽的柔韧性是通过第三个残基甘氨酸实现的。根据表面等离子共振（SPR）测量的结果计算结合亲和力、识别效率和定向因子。结果表明，解离常数为5.56×10(-10)M(-1)。我们还发现配体附着表面上的识别效率和定向因子远高于带负电和正电表面的识别效率和定向因子。该方法为定向抗体固定化的小配体设计提供了一种简单而快速的策略。
A new strategy for designing a short-chain peptide ligand with high affinity to the Fc region of an antibody was proposed. The targeted antibody is human prostate specific antibody (PSA) derived from Mouse IgG2a. The ligand design strategy involves two major parts: binding site selection and peptide ligand design. One of the exposed hydrophobic patches near the bottom of the antibody's Fc region, identified from the molecular docking of naphthelene and end-capped tryptophan, was selected as the binding site. After examining the charge distribution around the binding site, various peptide ligands were designed according to the possible hydrophobic and electrostatic interactions. A peptide ligand, RRGW, was found to have high Fc binding affinity by the analysis of molecular dynamics (MD) simulation. The first two residues, two arginines, play an important role in electrostatic interaction between the peptide and the Fc region of the antibody. The fourth residue, the tryptophan, provides the VDW force; and the flexibility of peptide is achieved through the help of the third residue, the glycine. The binding affinity, recognition efficiency, and orientation factor were calculated from the results of surface plasmon resonance (SPR) measurements. The result shows that the dissociation constant is 5.56 × 10(-10) M(-1). We also found that the recognition efficiency and orientation factor on the ligand attached surface were much higher than those on negatively and positively charged surfaces. This approach provides a simple and fast strategy for small ligands design on oriented antibody immobilization.