| Description |
PS(18:0/18:1(9Z)) is a phosphatidylserine. It is a glycerophospholipid in which a phosphorylserine moiety occupies a glycerol substitution site. As is the case with diacylglycerols, phosphatidylserines can have many different combinations of fatty acids of varying lengths and saturation attached to the C-1 and C-2 atoms. PS(18:0/18:1(9Z)), in particular, consists of one octadecanoyl chain to the C-1 atom, and one 9Z-octadecenoyl to the C-2 atom. Phosphatidylserine or 1,2-diacyl-sn-glycero-3-phospho-L-serine is distributed widely among animals, plants and microorganisms. Phosphatidylserine is an acidic (anionic) phospholipid with three ionizable groups, i.e. the phosphate moiety, the amino group and the carboxyl function. As with other acidic lipids, it exists in nature in salt form, but it has a high propensity to chelate to calcium via the charged oxygen atoms of both the carboxyl and phosphate moieties, modifying the conformation of the polar head group. This interaction may be of considerable relevance to the biological function of phosphatidylserine. While most phospholipids have a saturated fatty acid on C-1 and an unsaturated fatty acid on C-2 of the glycerol backbone, the fatty acid distribution at the C-1 and C-2 positions of glycerol within phospholipids is continually in flux, owing to phospholipid degradation and the continuous phospholipid remodeling that occurs while these molecules are in membranes. Phosphatidylserines typically carry a net charge of -1 at physiological pH. They mostly have palmitic or stearic acid on carbon 1 and a long chain unsaturated fatty acid (e.g. 18:2, 20:4 and 22:6) on carbon 2. PS biosynthesis involves an exchange reaction of serine for ethanolamine in PE. |
