Antifreeze proteins bind independently to ice.
It has been suggested that cooperative interactions between antifreeze proteins (AFPs) on the ice surfaces are required for complete inhibition of ice crystal growth. To test this hypothesis, a 7-kDa type III AFP was linked through its N-terminus to thioredoxin (12 kDa) or maltose-binding protein (42 kDa). The resultant 20-kDa and 50-kDa fusion proteins were larger in diameter than free AFP and thus precluded any extensive AFP-AFP contacts on the ice surface. Both fusion proteins were at least as active as free AFP at virtually all concentrations tested. By these criteria, AFPs function independently of each other and do not require specific intermolecular interactions to bind tightly to ice.
DeLuca
C I
CI
Department of Biochemistry, Queen's University, Kingston, Ontario, Canada.
Comley
R
R
Davies
P L
PL
D021301:Antifreeze Proteins; D001483:Base Sequence; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism; D005615:Freezing; D005813:Genes, Synthetic; D006023:Glycoproteins / Q000737:chemistry* / Q000378:metabolism; D007053:Ice; D058619:Maltose-Binding Proteins; D008958:Models, Molecular; D009838:Oligodeoxyribonucleotides; D011485:Protein Binding; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D013499:Surface Properties; D013879:Thioredoxins / Q000737:chemistry / Q000378:metabolism
D021301:Antifreeze Proteins; D002352:Carrier Proteins; D006023:Glycoproteins; D007053:Ice; D058619:Maltose-Binding Proteins; D009838:Oligodeoxyribonucleotides; D011993:Recombinant Fusion Proteins; D013879:Thioredoxins