Phospholipase A1 activity of crude enzyme extracted from the ovaries of skipjack tuna
Article first published online: 1 FEB 2008
© 2008 Japanese Society of Fisheries Science
Volume 74, Issue 1, pages 146–152, February 2008
How to Cite
HIRATSUKA, S., KITAGAWA, T., YAMAGISHI, K. and WADA, S. (2008), Phospholipase A1 activity of crude enzyme extracted from the ovaries of skipjack tuna. Fisheries Science, 74: 146–152. doi: 10.1111/j.1444-2906.2007.01504.x
- Issue published online: 1 FEB 2008
- Article first published online: 1 FEB 2008
- Received 28 March 2007. Accepted 30 July 2007.
- fatty acid;
- lipid class;
- phospholipase A1;
ABSTRACT: The phospholipid class composition, fatty acid composition and phospholipase A1 (PLA1) activity from the ovaries of skipjack tuna were compared with those of six other species of marine fish. In the skipjack ovaries, the lysophosphatidylcholine (LPC) proportion for the phospholipid, the docosahexaenoic acid (DHA) percentage for the total fatty acids of the phospholipids and the PLA1 activity of the crude enzyme were the highest among those of the seven species. The optimum pH and temperature for the PLA1 activity of the crude enzyme from the skipjack ovaries were in the range of pH 6–7 and 20–30°C, respectively, and calcium ions were not required. As a substrate, phosphatidylcholine was more easily hydrolyzed than phosphatidylethanolamine by this enzyme, and the plasmalogen-type phospholipid was much lower than the acyl-type phospholipid. After a 6-h hydrolysis reaction of the purified phospholipid extracted from the mixed ovaries of skipjack and yellowfin tuna by this enzyme, the LPC ratio of the phospholipid increased from 20 to 72.6% and the percentage of DHA for the total fatty acids of the phospholipid also increased. Thus, skipjack ovaries might possibly be used as a source of PLA1.