Institut Laue-Langevin

How Arctic fish’s antifreeze proteins work

Neutron scientists at ILL have discovered for the first time how ‘antifreeze’ in arctic fish blood kicks in to keep them alive in subzero conditions.

Biological antifreeze proteins (AFPs) are unusual proteins in several ways. They safeguard organisms from freezing to death by binding to ice crystal nuclei as soon as they start to form in bodily fluids, and prevent them from growing into ice crystals. However, AFPs must not attach to liquid water otherwise the organism would dehydrate and die. New research using neutrons provides the first experimental data showing how type-III AFPs, found in arctic fish blood, recognise the ice crystal nuclei. It found that unusual hydrophobic regions on the protein surface fit into ‘holes’ in the ice crystal nuclei structure.

The results could provide benefits for areas as diverse as cryosurgery, food processing and agriculture. [more]