Structure and function of antifreeze proteins.
High-resolution three-dimensional structures are now available for four of seven non-homologous fish and insect antifreeze proteins (AFPs). For each of these structures, the ice-binding site of the AFP has been defined by site-directed mutagenesis, and ice etching has indicated that the ice surface is bound by the AFP. A comparison of these extremely diverse ice-binding proteins shows that they have the following attributes in common. The binding sites are relatively flat and engage a substantial proportion of the protein's surface area in ice binding. They are also somewhat hydrophobic -- more so than that portion of the protein exposed to the solvent. Surface-surface complementarity appears to be the key to tight binding in which the contribution of hydrogen bonding seems to be secondary to van der Waals contacts.
Davies
Peter L
PL
Department of Biochemistry, Queen's University, Kingston, Ontario, Canada K7L 3N6. daviesp@post.queensu.ca
Baardsnes
Jason
J
Kuiper
Michael J
MJ
Walker
Virginia K
VK
D000818:Animals; D021301:Antifreeze Proteins / Q000737:chemistry* / Q000378:metabolism*; D019143:Evolution, Molecular; D005399:Fishes / Q000378:metabolism; D006860:Hydrogen Bonding; D007053:Ice; D019476:Insect Proteins / Q000737:chemistry / Q000378:metabolism; D007313:Insecta / Q000737:chemistry / Q000378:metabolism; D011487:Protein Conformation
D021301:Antifreeze Proteins; D007053:Ice; D019476:Insect Proteins