Molecular mechanisms of ion-specific effects on proteins. Academic Article uri icon

abstract

  • The specific binding sites of Hofmeister ions with an uncharged 600-residue elastin-like polypeptide, (VPGVG)(120), were elucidated using a combination of NMR and thermodynamic measurements along with molecular dynamics simulations. It was found that the large soft anions such as SCN(-) and I(-) interact with the polypeptide backbone via a hybrid binding site that consists of the amide nitrogen and the adjacent -carbon. The hydrocarbon groups at these sites bear a slight positive charge, which enhances anion binding without disrupting specific hydrogen bonds to water molecules. The hydrophobic side chains do not contribute significantly to anion binding or the corresponding salting-in behavior of the biopolymer. Cl(-) binds far more weakly to the amide nitrogen/-carbon binding site, while SO(4)(2-) is repelled from both the backbone and hydrophobic side chains of the polypeptide. The Na(+) counterions are also repelled from the polypeptide. The identification of these molecular-level binding sites provides new insights into the mechanism of peptide-anion interactions.

published proceedings

  • J Am Chem Soc

altmetric score

  • 0.25

author list (cited authors)

  • Rembert, K. B., Paterov, J., Heyda, J., Hilty, C., Jungwirth, P., & Cremer, P. S.

citation count

  • 241

complete list of authors

  • Rembert, Kelvin B||Paterov√°, Jana||Heyda, Jan||Hilty, Christian||Jungwirth, Pavel||Cremer, Paul S