Antifreeze proteins from the shorthorn sculpin, Myoxocephalus scorpius: isolation and characterization

Abstract

The antifreeze proteins (AFP) of the shorthorn sculpin, M. scorpius, were isolated and compared with the AFP of the winter flounder [Pseudopleuronectes americanus]. The shorthorn sculpin contained 1 major and 1 minor antifreeze protein with an approximate MW of 10,000-11,000 in the winter. The major AFP of the shorthorn sculpin had many characteristics in common with the flounder AFP. These characteristics included its seasonal appearance, size, amino acid composition, the abundance of alanine in the composition, the extent of antifreeze activity and the nature of the secondary structure. The sculpin and flounder AFP are structurally homologous and belong to the same type of polypeptide antifreeze.