Hydrophobic interactions are the driving force for the binding of peptide mimotopes and Staphylococcal protein A to recombinant human IgG1
Hydrophobic interactions are the driving force for the binding of peptide mimotopes and Staphylococcal protein A to recombinant human IgG1
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DOI：
10.1007/s00249-007-0140-8
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发表时间：
2007-07-01
影响因子：
2
通讯作者：
Blume, Alfred
中科院分区：
文献类型：
--
作者：
Arouri, Ahmad;Garidel, Patrick;Blume, Alfred
采用等温滴定量热法（ITC）研究了几种不同序列的九肽模拟表位和葡萄球菌蛋白A（SpA）与重组人IgG 1抗体的相互作用。改变肽的氨基酸一级结构以鉴定特异性抗体-肽结合位点。此外，温度和盐浓度的影响进行了研究。试图阐明复杂的形成后，使用确定的热力学参数的结构变化。模拟表位的氨基酸组成决定了它们的结合亲和力。模拟表位的结合常数Ka在1 × 10（4）至1 × 106 M-1的范围内。SpA的结合常数平均比肽高约三个数量级。的肽和SpA的结合常数随温度的降低和结合过程中连接的焓，熵和热容的负变化。模拟表位与IgG 1抗体Fab部分的结合以及SpA与IgG 1抗体Fe部分的结合主要由疏水效应驱动，并且与相对的疏水效应相关。
We studied the interaction of several nonapeptide mimotopes of different sequence and Staphylococcal protein A (SpA) with a recombinant human IgG1 antibody using isothermal titration calorimetry (ITC). The amino acid primary structure of the peptides was varied in order to identify the specific antibody-peptide binding sites. Additionally, the influence of temperature and salt concentration was investigated. An attempt was made to elucidate the structural changes upon complex formation using the determined thermodynamic parameters. The amino acid composition of the mimotopes determined their binding affinity. The binding constant Ka of the mimotopes was in the range 1 x 10(4) to 1 x 106 M-1. The binding constant of SpA was on the average about three orders of magnitude higher than that of the peptides. The binding constant of the peptides and of SpA decreased with temperature and the binding process was connected with negative changes in enthalpy, entropy, and heat capacity. The binding of the mimotopes to the Fab part of the IgG1 antibody and binding of SpA to the Fe part of the IgG1 antibody were mainly driven by hydrophobic effects and associated with a relatively