Dipalmitoylphosphatidylcholine
Encyclopedia
Dipalmitoylphosphatidylcholine (DpPC) is a phospholipid
(and a lecithin
) consisting of two palmitic acid
s and is the major constituent of pulmonary surfactant
. It is also the only surface active component of lung surfactant capable of lowering surface tension
to near zero levels. DpPC is synthesized mainly through remodeling of phosphatidylcholine
. It is thought that a lysophosphatidylcholine (lysoPC) acyltransferase may play a critical role in its synthesis. The identity of this acyltransferase has not yet been confirmed. Dipalmitoylphosphatidylcholine is an exception to the rule of thumb that biological phospholipids
are synthesized with a saturated fat at the R1 position and an unsaturated fat at the R2 position.
It is also used for research purposes in studying liposome
s, lipid bilayer
s, and model biological membrane
s and in the formation of reconstituted HDL (rHDL) particles.
Phospholipid
Phospholipids are a class of lipids that are a major component of all cell membranes as they can form lipid bilayers. Most phospholipids contain a diglyceride, a phosphate group, and a simple organic molecule such as choline; one exception to this rule is sphingomyelin, which is derived from...
(and a lecithin
Lecithin
Lecithin is a generic term to designate any group of yellow-brownish fatty substances occurring in animal and plant tissues, and in egg yolk, composed of phosphoric acid, choline, fatty acids, glycerol, glycolipids, triglycerides, and phospholipids .The word lecithin was originally coined in 1847 by...
) consisting of two palmitic acid
Palmitic acid
Palmitic acid, or hexadecanoic acid in IUPAC nomenclature, is one of the most common saturated fatty acids found in animals and plants. Its molecular formula is CH314CO2H. As its name indicates, it is a major component of the oil from palm trees . Palmitate is a term for the salts and esters of...
s and is the major constituent of pulmonary surfactant
Pulmonary surfactant
Pulmonary surfactant is a surface-active lipoprotein complex formed by type II alveolar cells. The proteins and lipids that surfactant comprises have both a hydrophilic region and a hydrophobic region...
. It is also the only surface active component of lung surfactant capable of lowering surface tension
Surface tension
Surface tension is a property of the surface of a liquid that allows it to resist an external force. It is revealed, for example, in floating of some objects on the surface of water, even though they are denser than water, and in the ability of some insects to run on the water surface...
to near zero levels. DpPC is synthesized mainly through remodeling of phosphatidylcholine
Phosphatidylcholine
Phosphatidylcholines are a class of phospholipids that incorporate choline as a headgroup.They are a major component of biological membranes and can be easily obtained from a variety of readily available sources such as egg yolk or soy beans from which they are mechanically extracted or chemically...
. It is thought that a lysophosphatidylcholine (lysoPC) acyltransferase may play a critical role in its synthesis. The identity of this acyltransferase has not yet been confirmed. Dipalmitoylphosphatidylcholine is an exception to the rule of thumb that biological phospholipids
Phospholipid
Phospholipids are a class of lipids that are a major component of all cell membranes as they can form lipid bilayers. Most phospholipids contain a diglyceride, a phosphate group, and a simple organic molecule such as choline; one exception to this rule is sphingomyelin, which is derived from...
are synthesized with a saturated fat at the R1 position and an unsaturated fat at the R2 position.
It is also used for research purposes in studying liposome
Liposome
Liposomes are artificially prepared vesicles made of lipid bilayer. Liposomes can be filled with drugs, and used to deliver drugs for cancer and other diseases. Liposomes are composite structures made of phospholipids and may contain small amounts of other molecules...
s, lipid bilayer
Lipid bilayer
The lipid bilayer is a thin membrane made of two layers of lipid molecules. These membranes are flat sheets that form a continuous barrier around cells. The cell membrane of almost all living organisms and many viruses are made of a lipid bilayer, as are the membranes surrounding the cell nucleus...
s, and model biological membrane
Biological membrane
A biological membrane or biomembrane is an enclosing or separatingmembrane that acts as a selective barrier, within or around a cell. It consists of a lipid bilayer with embedded proteins that may constitute close to 50% of membrane content...
s and in the formation of reconstituted HDL (rHDL) particles.