Top Qs
Timeline
Chat
Perspective
Pancreatic lipase family
Mammalian protein found in Homo sapiens From Wikipedia, the free encyclopedia
Remove ads
Pancreatic lipases (EC 3.1.1.3) are a family of lipolytic enzymes that hydrolyse ester linkages of triglycerides.[1] Lipases are widely distributed in animals, plants and prokaryotes.
At least three tissue-specific isozymes exist in higher vertebrates, pancreatic, hepatic and gastric/lingual. These lipases are closely related to each other and to lipoprotein lipase (EC 3.1.1.34), which hydrolyses triglycerides of chylomicrons and very low density lipoproteins (VLDL).[2]
Pancreatic lipase contains two protein domains. The one toward the N terminus is an α/β hydrolase, whereas the one toward the C terminus plays a role in binding to colipase, a protein needed in order for the lipase to become activated.[3]
The most conserved region in all these proteins is centred on a serine residue which has been shown[4] to participate, with a histidine and an aspartic acid residue, in a charge relay system. Such a region is also present in lipases of prokaryotic origin and in lecithin-cholesterol acyltransferase (EC 2.3.1.43) (LCAT),[5] which catalyzes fatty acid transfer between phosphatidylcholine and cholesterol.
Remove ads
Human pancreatic lipase
Summarize
Perspective
Pancreatic lipase, also known as pancreatic triacylglycerol lipase or steapsin, is an enzyme secreted from the pancreas. As the primary lipase enzyme that hydrolyzes (breaks down) dietary fat molecules in the human digestive system, it is one of the main digestive enzymes, converting triglyceride substrates like 1 found in ingested oils to monoglycerides 3 and free fatty acids 2a and 2b.[6]
Bile salts secreted from the liver and stored in gallbladder are released into the duodenum, where they coat and emulsify large fat droplets into smaller droplets, thus increasing the overall surface area of the fat, which allows the lipase to break apart the fat more effectively. The resulting monomers (2 free fatty acids and one 2-monoacylglycerol) are then moved by way of peristalsis along the small intestine to be absorbed into the lymphatic system by a specialized vessel called a lacteal.
Unlike some pancreatic enzymes that are activated by proteolytic cleavage (e.g., trypsinogen), pancreatic lipase is secreted in its final form. However, it becomes efficient only in the presence of colipase in the duodenum.
In humans, pancreatic lipase is encoded by the PNLIP gene.[7][8]
Human proteins containing this domain
Diagnostic importance
Pancreatic lipase is secreted into the duodenum through the duct system of the pancreas. Its concentration in serum is normally very low. Under extreme disruption of pancreatic function, such as pancreatitis or pancreatic adenocarcinoma, the pancreas may begin to autolyse and release pancreatic enzymes including pancreatic lipase into serum. Thus, through measurement of serum concentration of pancreatic lipase, acute pancreatitis can be diagnosed.[9]
Inhibitors
Lipase inhibitors such as orlistat can be used as a treatment for obesity.[10]
One peptide selected by phage display was found to inhibit pancreatic lipase.[11]
Remove ads
See also
References
Further reading
Wikiwand - on
Seamless Wikipedia browsing. On steroids.
Remove ads