A BIOCHEMICAL-CHARACTERIZATION OF VITELLOGENINS ISOLATED FROM THE MARINE FISH OCEAN POUT (MACROZOARCES-AMERICANUS L), LUMPFISH (CYCLOPTERUS-LUMPUS) AND ATLANTIC COD (GADUS-MORHUA)

Vitellogenins (VTGs) were isolated from three marine teleosts, the oce an pout (Macrozoarces americanus), lumpfish (Cyclopterus lumpus) and A tlantic cod (Gadus morhua), for the analysis of amino-acid composition and other partial biochemical characterizations. All three VTGs conta ined high levels of essential amino acids, arginine (5.08-6.54%), lysi ne (8.44-8.74%), isoleucine (5.60-6.82%), leucine (9.61-11.39%) and va line (6.76-6.99%). While histidine (2.27-2.67%) levels were low, the l evels of methionine (1.51-3.38%), threonine (4.69-6.09%) and phenylala nine (3.38-4.41%) varied between species. In the category of non essen tial amino acids, aspartic acid (8.60-9.68%), serine (6.09-7.68%), glu tamic acid (11.45-11.97%) and alanine (6.49-7.79%) were predominant. S imilarity was also noted in the VTG content of protein-hound phosphoru s (0.62-0.72%) as well as total lipid (17.92-21.34%) among the three s pecies. However, the molecular weights (485-630 KD), total phosphorus (2.15-3.56%) and the lipid-bound phosphorus contents (1.51-2.86%) of t he VTGs varied. VTGs from the Atlantic cod and lumpfish did not cross- react with the antibodies made against ocean pout VTG, suggesting that VTG is species-specific.