Antifreeze glycoproteins from Polar fish. Structural requirements for function of glycopeptide 8.

Antifreeze glycoproteins from Arctic fish.

Four species of fish in the Barents Sea of the Arctic, north of Norway and Russia, were caught and examined for the presence of antifreeze proteins in their blood sera. Only one species of Arctic fish, the polar cod (Boreogadus saida), was found to contain an antifreeze protein. Antifreeze glycoproteins were isolated and characterized from the blood serum of the Arctic fish, and their structure...

Antifreeze Glycoproteins from an Antarctic Fish

A quasi-elastic light-scattering technique was used to study the hydrodynamic conformations of antifreeze glycoproteins from an Antarctic fish. Antifreeze glycoprotein is composed of repeating units of Ala-Ala-Thr, with each threonine O-linked to a disaccharide, and it exists as several polymers of different numbers of this repeating unit. Molecular weights of the two major active polymers are ...

Antifreeze glycopeptide diastereomers

Antifreeze glycopeptides (AFGPs) are a special class of biological antifreeze agents, which possess the property to inhibit ice growth in the body fluids of arctic and antarctic fish and, thus, enable life under these harsh conditions. AFGPs are composed of 4-55 tripeptide units -Ala-Ala-Thr- glycosylated at the threonine side chains. Despite the structural homology among all the fish species, ...

Comparison of the solution conformation and dynamics of antifreeze glycoproteins from Antarctic fish.

The (1)H- and (13)C-NMR spectra of antifreeze glycoprotein fractions 1-5 from Antarctic cod have been assigned, and the dynamics have been measured using (13)C relaxation at two temperatures. The chemical shifts and absence of non-sequential (1)H-(1)H NOEs are inconsistent with a folded, compact structure. (13)C relaxation measurements show that the protein has no significant long-range order, ...

Origin and Mechanism of Evolution of Antifreeze Glycoproteins in Polar Fishes