The role of sulfates on antifreeze protein activity

Konrad Meister, John G. Duman, Yao Xu, Arthur L. DeVries, David M. Leitner, Martina Havenith

Research output: Contribution to journalArticlepeer-review

Abstract

In the present study, we have investigated the effect of sodium sulfate (Na2SO4) buffer on the antifreeze activity of DAFP-1, the primary AFP in the hemolymph of the beetle Dendroides canadensis. In contrast to previous studies, we found evidence that sodium sulfate does not suppress antifreeze activity of DAFP-1. Terahertz absorption spectroscopy (THz) studies were combined with molecular dynamics (MD) simulations to investigate the change in collective hydrogen bond dynamics in the vicinity of the AFP upon addition of sodium sulfate. The MD simulations revealed that the gradient of H-bond dynamics toward the ice-binding site is even more pronounced when adding sodium sulfate: The cosolute dramatically slows the hydrogen bond dynamics on the ice-binding plane of DAFP-1, whereas it has a more modest effect in the vicinity of other parts of the protein. These theoretical predictions are in agreement with the experimentally observed increase in THz absorption for solvated DAFP-1 upon addition of sodium sulfate. These studies support our previously postulated mechanism for AF activity, with a preferred ice binding by threonine on nanoice crystals which is supported by a long-range effect on hydrogen bond dynamics.

Original languageEnglish (US)
Pages (from-to)7920-7924
Number of pages5
JournalJournal of Physical Chemistry B
Volume118
Issue number28
DOIs
StatePublished - Jul 17 2014

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films
  • Materials Chemistry

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