Identification of the ice-binding face of a plant antifreeze protein

FEBS Lett. 2009 Feb 18;583(4):815-9. doi: 10.1016/j.febslet.2009.01.035. Epub 2009 Jan 29.


The antifreeze protein of Lolium perenne, a perennial ryegrass, was previously modeled as a beta-roll with two extensive flat beta-sheets on opposite sides of the molecule. Here we have validated the model with a series of nine site-directed steric mutations in which outward-pointing short side-chain residues were replaced by tyrosine. None of these disrupted the fold. Mutations on one of the beta-sheets and on the sides of the protein retained 70% or greater activity. Three mutations that clustered on the other flat surface lost up to 90% of their antifreeze activity and identify this beta-sheet as the ice-binding face.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Antifreeze Proteins / chemistry*
  • Antifreeze Proteins / genetics
  • Antifreeze Proteins / isolation & purification
  • Antifreeze Proteins / metabolism*
  • Binding Sites / genetics
  • Escherichia coli / genetics
  • Hydrophobic and Hydrophilic Interactions
  • Lolium / genetics
  • Lolium / metabolism
  • Models, Molecular
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Mutation
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Protein Binding / genetics
  • Protein Folding
  • Protein Structure, Secondary
  • Reproducibility of Results
  • Sequence Homology, Amino Acid
  • Surface Properties
  • Tyrosine / metabolism


  • Antifreeze Proteins
  • Plant Proteins
  • Tyrosine