PA, LPA, & Cyclic LPA

Phosphatidic acid (PA) and lysophosphatidic acid (LPA) are simple, but important anionic bioactive lipids and are involved in a number of cellular processes. LPA carries a more negative charge in phospholipid bilayers than does PA. This is likely due to the hydroxyl group on LPA’s backbone and how it interacts with the phosphomonoester headgroup. The charge of PA or LPA headgroups is largely dependent on the local lipid composition in phospholipid bilayers. The hydrogen bond property of PA and LPA have been proposed to play a key role in the various cellular functions of these lipids.

Cyclic PA is a naturally occurring analog of LPA. CPA affects various cellular functions including antimitogenic regulation of cells, induction of stress fiber formation, inhibition of tumor cell invasion, and regulation of survival neuronal cells. Interestingly, the functions of CPA seem to oppose the cellular functions of LPA. CPA has been extracted from human serum albumin. ESI-MS/MS analysis revealed that 16:0 CPA was the most abundant CPA species and that 14:0 and 18:0 CPA were found to be present as minor species.

Kooijman EE, Carter KM, van Laar EG, Chupin V, Burger KN, de Kruijff B. What makes the bioactive lipids phosphatidic acid and lysophosphatidic acid so special? Biochemistry. 2005 Dec 27;44(51):17007-15. DOI: 10.1021/bi0518794. PMID: 16363814.

Fujiwara Y. Cyclic phosphatidic acid - a unique bioactive phospholipid. Biochim Biophys Acta. 2008;1781(9):519-524. doi:10.1016/j.bbalip.2008.05.002