Hydration shells exchange charge with their protein

Haim Abitan, Per-Anker Lindgård, Bjørn Gilbert Nielsen, M.S. Larsen, Henrik Bohr

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Investigation of the interaction between a protein and its hydration shells is an experimental and theoretical challenge. Here, we used ultrasonic pressure waves in aqueous solutions of a protein to explore the conformational states of the protein and its interaction with its hydration shells. In our experiments, the amplitude of an ultrasonic pressure wave is gradually increased (0–20 atm) while we simultaneously measure the Raman spectra from the hydrated protein (β-lactoglobulin and lysozyme). We detected two types of spectral changes: first, up to 70% increase in the intensity of the fluorescence background of the Raman spectrum with a typical relaxation time of 30–45 min. Second, we detect changes in the vibrational Raman spectra. To clarify these results we conducted similar experiments with aqueous solutions of amino acids and ethanol. These experiments led us to conclude that, without the presence of an ultrasonic pressure, a protein and its hydration shells are in thermodynamic and charge equilibrium, i.e. a protein and its hydration shells exchange charges. The ultrasonic wave disrupts these equilibria which are regained within 30–45 min after the ultrasonic pressure is shut off.
Original languageEnglish
JournalJournal of Physics: Condensed Matter
Volume22
Issue number36
Pages (from-to)365102
ISSN0953-8984
DOIs
Publication statusPublished - 2010

Keywords

  • Materials and energy storage
  • Superconducting materials

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