Production of bioactive lysophosphatidic acid by lysophospholipase D in hen egg white

详细信息	查看全文 | 推荐本文 |

• 作者：Junichi Morishige ; Kanako Touchika ; Tamotsu Tanaka ; Kiyoshi Satouchi ; Kenji Fukuzawa ; Akira Tokumura
• 关键词：Autotaxin ; Choline ; Egg white ; Lysophosphatidic acid ; Lysophospholipase D ; Lysozyme
• 刊名：Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids
• 出版年：2007
• 期刊代码：18_13881981
• 类别：bio
• 出版时间：April 2007
• 卷：1771
• 期：4
• 页码：491-499
• 文件大小：399 K

摘要

Lysophosphatidic acid (LPA), a lysophospholipid mediator, is produced extracellularly by lysophospholipase D (lysoPLD) secreted in several animal body fluids including blood plasma. Previously, we reported that hen egg white contains polyunsaturated fatty acid-rich LPA. In this study, we examined whether lysoPLD is involved in the production of LPA in hen egg white. LysoPLD activity was measured by determining LPA and choline by mass spectrometric and enzyme-linked fluorometric analyses, respectively. LysoPLD increased with increased dilution of egg white, indicating that one or more components of egg white strongly inhibit its lysoPLD activity. This dilution-dependent increase in the lysoPLD activity was masked by co-incubation of the egg white with lysozyme, a major protein in hen egg white. Furthermore, addition of Zn²⁺, Mn²⁺, Ni²⁺, or Co²⁺ to diluted egg white altered preference patterns of lysoPLD toward choline-containing substrates. In particular, the egg white lysoPLD activity was greatly increased when Co²⁺ was added. The cation-requirement of lysoPLD activity in hen egg white resembled that of plasma autotaxin (ATX)/lysoPLD. Western blot analysis revealed that egg white contained a protein that was immunostained with anti-ATX antibody. These results suggested that LPA in hen egg white is produced from lysophospholipids, especially LPC, by the action of ATX/lysoPLD, possibly originating from hen oviduct fluid.