Abstract
Although effective liquid chromatography (LC)/mass spectrometry (MS) methods enabling the separation of phospholipid molecular species have been developed, there are still problems with an intracellular signaling molecule, phosphatidic acid (PA). In this study, we optimized LC/MS conditions to improve the quantitative detection of PA molecular species from a cellular lipid mixture. Using the newly developed LC/MS method, we showed that stimulation of CTLL‐2 murine T‐lymphocytes by interleukin‐2 (IL‐2) induced a significant increase of 36:1‐, 36:2‐, 40:5‐ and 40:6‐diacyl‐PA. A diacylglycerol kinase (DGK) inhibitor, R59949, attenuated the increase of 36:1‐, 40:5‐, 40:6‐diacyl‐PA, suggesting that DGK IL‐2‐dependently and selectively generated these diacyl‐PA species.