IDENTIFICATION AND CHARACTERIZATION OF A 15-LIPOXYGENASE FROM FISH GILLS

An arachidonic acid 15-lipoxygenase activity was discovered in the gill tissue of teleost fishes during purification of the previously recognized and more preponderant 12-lipoxygenase enzyme. The total activity of this enzyme following purification using hydroxylapatite was significantly greater than in the crude tissue preparation, suggesting that an inhibition was removed during purification. The enzyme was active toward polyunsaturated fatty acids present in the tissue producing hydroxylated metabolites from fatty acids with 18-, 20-, and 22-carbon chain lengths at carbons 13, 15, and 17, respectively. The enzyme was further purified by using a Superose gel filtration column and eluted with an apparent molecular weight of 70 000.