High Water Density at Non-Ice-Binding Surfaces Contributes to the Hyperactivity of Antifreeze Proteins

J Phys Chem Lett. 2021 Sep 16;12(36):8777-8783. doi: 10.1021/acs.jpclett.1c01855. Epub 2021 Sep 7.

Abstract

Antifreeze proteins (AFPs) can bind to ice nuclei thereby inhibiting their growth and their hydration shell is believed to play a fundamental role. Here, we use molecular dynamics simulations to characterize the hydration shell of four moderately-active and four hyperactive AFPs. The local water density around the ice-binding-surface (IBS) is found to be lower than that around the non-ice-binding surface (NIBS) and this difference correlates with the higher hydrophobicity of the former. While the water-density increase (with respect to bulk) around the IBS is similar between moderately-active and hyperactive AFPs, it differs around the NIBS, being higher for the hyperactive AFPs. We hypothesize that while the lower water density at the IBS can pave the way to protein binding to ice nuclei, irrespective of the antifreeze activity, the higher density at the NIBS of the hyperactive AFPs contribute to their enhanced ability in inhibiting ice growth around the bound AFPs.

MeSH terms

  • Aeromonadaceae / chemistry
  • Antifreeze Proteins / chemistry*
  • Bacterial Proteins / chemistry*
  • Basidiomycota / chemistry
  • Crystallization
  • Granulovirus / chemistry
  • Hydrophobic and Hydrophilic Interactions
  • Ice
  • Isomerism
  • Molecular Dynamics Simulation
  • Protein Binding
  • Protein Conformation
  • Surface Properties
  • Temperature

Substances

  • Antifreeze Proteins
  • Bacterial Proteins
  • Ice

Supplementary concepts

  • Choristoneura fumiferana granulovirus
  • Typhula ishikariensis
  • Zobellella aerophila