Antifreeze glycoproteins in the plasma of Newfoundland Atlantic cod ( Gadus morhua )

The plasma of the Atlantic cod, Gadus morhua, contained antifreeze glycoproteins which were present only during the winter months. The antifreeze proteins were isolated, using gel filtration and ion exchange chromatography, and characterized by high performance liquid chromatography. The antifreeze...

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Bibliographic Details
Published in:Canadian Journal of Zoology
Main Authors: Hew, Choy L., Slaughter, Don, Fletcher, Garth L., Joshi, Shashikant B.
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 1981
Subjects:
Online Access:http://dx.doi.org/10.1139/z81-296
http://www.nrcresearchpress.com/doi/pdf/10.1139/z81-296
Description
Summary:The plasma of the Atlantic cod, Gadus morhua, contained antifreeze glycoproteins which were present only during the winter months. The antifreeze proteins were isolated, using gel filtration and ion exchange chromatography, and characterized by high performance liquid chromatography. The antifreeze proteins appeared to consist of at least seven components with molecular weights ranging from 2 500 to 33 000. Chemical analysis of the larger components showed a predominance of alanine, threonine, and galactosamine in a ratio of 2:1:1. The smaller peptides contained proline, in addition to alanine and threonine. The amino acid sequence of the smallest glycopeptide (molecular weight 2500) was found to be Ala Ala Thr Pro Ala Thr Ala Ala Thr Pro Ala Thr Ala Ala.These glycoproteins are very similar, if not identical, in amino acid and carbohydrate composition to those isolated from Antaractic nototheniids and several northern gadoids. The sequence of the smallest glycopeptide from the Atlantic cod is identical to that reported for the polar cod, Boreogadus saida.