Contribution of acidic amino residues to the adsorption of peptides onto a stainless steel surface

Koreyoshi Imamura, Yuuki Kawasaki, Tomoka Awadzu, Takaharu Sakiyama, Kazuhiro Nakanishi

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38 Citations (Scopus)

Abstract

The role of the acidic amino acid residues in the adsorption of peptides/proteins onto stainless steel particles was investigated using a peptide fragment from bovine β-lactoglobulin, Thr-Pro-Glu-Val-Asp-Asp-Glu- Ala-Leu-Glu-Lys (T5 peptide), which has a high affinity to a stainless steel surface at acidic pHs, and its mutant peptides substituted with different numbers of acidic amino acid residues. The adsorption behavior of the mutant peptides as well as the T5 peptide were studied at pH 3 with respect to concentration and ionic strength dependencies and the reversibility of the adsorption process. The behavior of the peptides was generally characterized as two distinct irreversible adsorption modes, Mode I and Mode II. In Mode I, the amounts adsorbed lay on the ordinate at zero equilibrium concentration in the solution, while in Mode II, the amount adsorbed increased with increased equilibrium concentration. The area occupied by the peptides was predicted by molecular mechanics and molecular dynamics. The state of the peptides, when adsorbed, was investigated using FT-IR analysis. The FT-IR analyses revealed that the side carboxylic groups of the peptides adsorbed on the stainless steel surface were ionized, while they were unionized in the solution at pH 3. Thus, the interactions between the carboxylic groups of the peptide and the stainless steel surface can be considered to be largely electrostatic. The peptide having four acidic amino acid residues took a maximum adsorbed amount, the reason for which is discussed.

Original languageEnglish
Pages (from-to)294-301
Number of pages8
JournalJournal of Colloid and Interface Science
Volume267
Issue number2
DOIs
Publication statusPublished - Nov 15 2003

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Keywords

  • Adsorption
  • FT-IR
  • Peptide
  • Stainless steel surface

ASJC Scopus subject areas

  • Colloid and Surface Chemistry
  • Physical and Theoretical Chemistry
  • Surfaces and Interfaces

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