Insects that experience temperatures below 0°C have evolved proteins to slow or
ID: 140553 • Letter: I
Question
Insects that experience temperatures below 0°C have evolved proteins to slow or minimizethe growth of ice crystals. Recall that ice occupies more volume than liquid water. Formation of ice in the insects body could expand the body enough that it ruptures and kills the insect.Antifreeze proteins differ among insect species, but many share a common structural feature of a flat surface with many exposed hydroxyl (-OH) groups from threonine amino acids making up the protein .Propose a mechanism for how this structural feature minimizes
Explanation / Answer
Antifreeze proteins to minimize the growth of ice crystals must have a tricky job. They bind to ice crystals to prevent their growth while engulfed by much larger amounts of liquid water. As many antifreeze proteins in insects share particular arangement of threonine amino acids that form an ice-binding site. So this is how structural feature minimizes the growth of ice crystals inside the body of insect. Also there can be interaction between an antifreeze protein and water molecules, as antifreeze proteins affects the organization of water molecules upto seven layers of water, away from the ice-binding site. This long range interaction affects hydrogen bonding and might interferes with the ice formation.