Adsorption mechanism at the molecular level between polymers and uremic octapeptide by the 2D 1H NMR Technique.
Adsorption mechanism at the molecular level between polymers and uremic octapeptide by the 2D 1H NMR Technique.
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DOI：
10.1021/bm060126
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发表时间：
2006-05
影响因子：
6.2
通讯作者：
Guohua Li;Jihong Li;Wei Wang;Mei Yang;Yuanwei Zhang;Pingchuan Sun;Zhi Yuan;B. He;Yao-ting Yu
中科院分区：
文献类型：
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作者：
Guohua Li;Jihong Li;Wei Wang;Mei Yang;Yuanwei Zhang;Pingchuan Sun;Zhi Yuan;B. He;Yao-ting Yu
为清除尿毒症患者血液中的尿毒症八肽，制备了各种改性聚丙烯酰胺交联吸附剂。吸附实验表明，这些吸附剂对目标肽的吸附能力有显著差异。本文采用二维核磁共振氢谱（2D 1HNMR）研究了多肽与吸附剂的相互作用机理。由于吸附剂的不溶性，一些可溶性的线性聚合物具有相同的功能基团的吸附剂作为模型吸附剂在二维1H NMR。肽和聚合物的优选结合位点被确定为通过化学位移扰动效应在八肽的C-末端羧基。在这项研究中，我们发现氢键，静电和疏水相互作用都发挥了作用的相互作用力，但有不同的贡献。特别是芳香族氨基酸残基（Trp）在丁基改性聚丙烯酰胺与八肽相互作用过程中的化学位移变化，表明疏水相互作用结合静电力在水溶液中的结合反应中起着重要作用。这些信息不仅合理地解释了吸附实验的结果，而且确定了有效的结合位点和机制，并将为设计更好的亲和型吸附剂的目标肽提供结构基础。
To remove uremic octapeptide from the blood stream of uremic patients, various modified polyacylamide cross-linked absorbents were prepared. Adsorption experiments showed these absorbents have significant differences in adsorption capacity to the target peptide. In this paper, two-dimension proton nuclear magnetic resonance (2D 1H NMR) spectroscopy was used to investigate the interaction mechanism between the peptide and the adsorbents. Because of the insolubility of the absorbent, some soluble linear polymers with the same functional groups as the absorbents were employed as the model adsorbents in 2D 1H NMR. The preferred binding site for the peptide and polymers was identified to be at the C-terminal carboxyl group of the octapeptide via chemical shift perturbation effects. In this study, we found that hydrogen bonding, electrostatic, and hydrophobic interactions all play a role in the interaction force but had different contributions. Especially, the great chemical shift changes of the aromatic amino acid residues (Trp) during the interaction between butyl-modified polyacrylamide and octapeptide suggested the hydrophobic interaction, incorporated with the electrostatic force, played an important role in the binding reaction in aqueous solutions. This information not only rationally explained the results of the adsorption experiments, but also identified the effective binding site and mechanism, and shall provide a structural basis for designing better affinity-type adsorbents for the target peptide.