Human Lipases
The main lipases of the human digestive system are human pancreatic lipase (HPL) and pancreatic lipase related protein 2 (PLRP2), which are secreted by the pancreas. Humans also have several other related enzymes, including hepatic lipase (HL), endothelial lipase, and lipoprotein lipase. Not all of these lipases function in the gut (see table).
| Name | Gene | Location | Description | Disorder |
| bile salt dependent lipase | ? | pancreas, breast milk | aids in the digestion of fats | |
| pancreatic lipase | PNLIP | digestive juice | In order to exhibit optimal enzyme activity in the gut lumen, HPL requires another protein, colipase, which is also secreted by the pancreas. | |
| lysosomal lipase | LIPA | interior space of organelle: lysosome | Also referred to as lysosomal acid lipase (LAL or LIPA) or acid cholesteryl ester hydrolase | Cholesteryl ester storage disease (CESD) and Wolman disease are both caused by mutations in the gene encoding lysosomal lipase. |
| hepatic lipase | LIPC | endothelium | Hepatic lipase acts on the remaining lipids carried on lipoproteins in the blood to regenerate LDL (low density lipoprotein). | - |
| lipoprotein lipase | LPL or "LIPD" | endothelium | Lipoprotein lipase functions in the blood to act on triacylglycerides carried on VLDL (very low density lipoprotein) so that cells can take up the freed fatty acids. | Lipoprotein lipase deficiency is caused by mutations in the gene encoding lipoprotein lipase. |
| hormone-sensitive lipase | LIPE | intracellular | - | - |
| gastric lipase | LIPF | digestive juice | Functions in the infant at a near-neutral pH to aid in the digestion of lipids | - |
| endothelial lipase | LIPG | endothelium | - | - |
| pancreatic lipase related protein 2 | PNLIPRP2 or "PLRP2" - | digestive juice | - | - |
| pancreatic lipase related protein 1 | PNLIPRP1 or "PLRP1" | digestive juice | Pancreatic lipase related protein 1 is very similar to PLRP2 and HPL by amino acid sequence (all three genes probably arose via gene duplication of a single ancestral pancreatic lipase gene). However, PLRP1 is devoid of detectable lipase activity and its function remains unknown, even though it is conserved in other mammals. | - |
| lingual lipase | ? | digestive juice | Active at gastric pH levels. Optimum pH is about 3.5-6. Screted by the Parotid and Ebner's glands at the back of the tongue. | - |
Other lipases include LIPH, LIPI, LIPJ, LIPK, LIPM, LIPN, MGLL, DAGLA, DAGLB, and CEL.
There also are a diverse array of phospholipases, but these are not always classified with the other lipases.
Read more about this topic: Lipase
Famous quotes containing the word human:
“America did not invent human rights. In a very real sense ... human rights invented America.”
—Jimmy Carter (James Earl Carter, Jr.)