Adsorption mechanism at the molecular level between polymers and uremic octapeptide by the 2d 1H NMR technique

Guohua Li, Jihong Li, Wei Wang, Mei Yang, Yuanwei Zhang, Pingchuan Sun, Zhi Yuan, Binglin He, Yaoting Yu

Research output: Contribution to journalArticle

14 Scopus citations

Abstract

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

Original languageEnglish (US)
Pages (from-to)1811-1818
Number of pages8
JournalBiomacromolecules
Volume7
Issue number6
DOIs
StatePublished - Jun 1 2006

All Science Journal Classification (ASJC) codes

  • Bioengineering
  • Materials Chemistry
  • Polymers and Plastics
  • Biomaterials

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