Antifreeze protein

Function

Antifreeze protein (AFP) permits the survival of certain organisms in subzero temperatures. AFP binds to small ice crystals thus inhibiting their growth.^[1]. There are 3 types of AFP which differ in the ice crusts face to which they bind^[2].

• AFP I is Ala-rich and alpha helical
  
• AFP II is Cys-rich and globular
  
• AFP III is globular
  
• For winter flounder antifreeze protein type I see User:Mary Ball/AFP.
  
• For snow flea antifreeze protein see Sandox 2pne
• For insect antifreeze protein see RiAFP
• For yellow mealworm antifreeze protein see Tenebrio molitor Antifreeze Protein (TmAFP).

Relevance

AFPs are added to ice cream and yogurt. AFPs are tested as freeze tolerant for crops, cryosurgery, hypothermia therapy, food preservation and tissue transplant preservation.

Structural highlights

at distances which match those of the primary prism plane of ice thus allowing for favorable interactions between the protein and ice crystals. Fungal antifreeze protein (PDB code 3vn3)^[3] is shown.

3D Structures of antifreeze protein

Antifreeze protein 3D structures