Salicylhydroxamic acid inhibits v6 desaturation in the microalga Porphyridium cruentum1 Academic Article uri icon


  • Abstract Treatment of the microalga Porphyridium cruentum with salicylhydroxamic acid (SHAM) inhibited growth and affected fatty acid composition. At a relatively low concentration (40 WM) SHAM predominantly inhibits v6 desaturation. The effect of the inhibitor was most intense in phosphatidylcholine (PC) and phosphatidylethanolamine, in which the proportions of the downstream products of the v6 desaturase were reduced, whereas that of the substrate, 18: 2, increased. As a result of the availability of 18: 2, 18: 3g3, which under normal conditions is not observed, appeared predominantly in chloroplastic lipids. Pulse labeling with linoleic acid has shown that SHAM inhibits v6 desaturation almost immediately, suggesting an apparent inhibition of the activity of the desaturase, rather than its synthesis or that of its cofactors. Furthermore, the addition of Q-linolenic acid to SHAM …

publication date

  • January 1, 1999