Local ice melting by an antifreeze protein

Biomacromolecules. 2012 Jul 9;13(7):2046-52. doi: 10.1021/bm300366f. Epub 2012 Jun 15.

Abstract

Antifreeze proteins, AFP, impede freezing of bodily fluids and damaging of cellular tissues by low temperatures. Adsorption-inhibition mechanisms have been developed to explain their functioning. Using in silico Molecular Dynamics, we show that type I AFP can also induce melting of the local ice surface. Simulations of antifreeze-positive and antifreeze-negative mutants show a clear correlation between melting induction and antifreeze activity. The presence of local melting adds a function to type I AFPs that is unique to these proteins. It may also explain some apparently conflicting experimental results where binding to ice appears both quasipermanent and reversible.

MeSH terms

  • Amino Acid Substitution
  • Antifreeze Proteins, Type I / chemistry*
  • Fish Proteins / chemistry*
  • Freezing*
  • Hydrogen Bonding
  • Molecular Dynamics Simulation*
  • Principal Component Analysis
  • Protein Structure, Secondary
  • Transition Temperature
  • Water / chemistry*

Substances

  • Antifreeze Proteins, Type I
  • Fish Proteins
  • Water