Enlarge
16:0-18:1 PS (POPS) 840034 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine (sodium salt)
With a gel-to-liquid crystalline transition temperature of ~14 °C, POPS readily forms fluid bilayers under typical lab and physiological conditions. Membranes incorporating this lipid, therefore, remain dynamic at room temperature and above, making POPS well-suited for the construction of model membrane systems.
In living cells, phosphatidylserine (PS) resides mainly on the inner leaflet of the plasma membrane. When cells undergo apoptosis, however, PS redistributes to the outer membrane. This externalization event functions as a key biological signal, flagging dying cells for clearance by phagocytes and creating a catalytic surface that supports assembly of coagulation enzyme complexes.
Applications
- Apoptosis detection and efferocytosis studies: POPS liposomes and supported bilayers replicate the phosphatidylserine-rich outer membrane of apoptotic cells, enabling studies of PS recognition by receptors such as TIM-4, BAI1, and TAM kinases; they are also used in assays involving the apoptosis probe Annexin V.
- Blood coagulation research: Liposomes containing defined POPC/POPS ratios recreate the phospholipid surfaces required for prothrombinase and tenase complex assembly, allowing researchers to measure thrombin generation and evaluate PS-binding anticoagulants.
- Model membranes for membrane biophysics: POPS is widely incorporated into bilayer systems that mimic the inner leaflet of eukaryotic plasma membranes; these models support studies of ion-lipid interactions, calcium-driven domain formation, and protein binding.
- Structural and computational lipid studies: POPS serves as a benchmark lipid in molecular dynamics simulations and experimental characterization methods such as SAXS, SANS, Langmuir monolayers, and scanning probe microscopy.
Formulation & handling
16:0–18:1 PS dissolves in DMSO and in chloroform:methanol:water (65:25:4) at approximately 5mg/mL.
To prepare liposomes, dissolve POPS alongside other lipids, such as POPC and cholesterol, in an organic solvent mixture. Remove the solvent by rotary evaporation until a thin lipid film forms, then hydrate it with aqueous buffer at a temperature above the TM (14 °C); room-temperature hydration generally works well. Vesicle size can then be reduced through extrusion or sonication.
Avanti Research™ provides POPS as sodium salt manufactured to >99% purity. Because POPS readily absorbs moisture, handle the material under inert gas (nitrogen or argon) when possible. Store the lipid desiccated at –20 °C to maintain its stability. It remains stable for up to one year.
