Pancreatic lipase

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Pancreatic lipase
Pancreatic lipase–colipase complex with inhibitor 1LPB.png
Cartoon diagram of human pancreatic lipase (colored by secondary structure: alpha helices in red, beta sheets in yellow, and random coil in green) in complex with pig colipase (colored blue) and a small molecule inhibitor (upper left).[1]
Available structures
PDB Ortholog search: PDBe, RCSB
Identifiers
Symbols PNLIP ; PL; PNLIPD; PTL
External IDs OMIM246600 MGI97722 HomoloGene30999 ChEMBL: 1812 GeneCards: PNLIP Gene
EC number 3.1.1.3
Orthologs
Species Human Mouse
Entrez 5406 69060
Ensembl ENSG00000175535 ENSMUSG00000046008
UniProt P16233 Q6P8U6
RefSeq (mRNA) NM_000936 NM_026925
RefSeq (protein) NP_000927 NP_081201
Location (UCSC) Chr 10:
118.31 – 118.33 Mb
Chr 19:
58.67 – 58.68 Mb
PubMed search [1] [2]

Pancreatic lipase, also known as pancreatic triacylglycerol lipase, is secreted from the pancreas, and is the primary lipase (enzyme) that hydrolyzes (breaks down) dietary fat molecules in the human digestive system, converting triglyceride substrates found in ingested oils to monoglycerides and free fatty acids.

Triacylglycerol + 2 H2O \rightleftharpoons 2-monoacylglycerol + 2 fatty acid anions

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. This protein belongs to pancreatic lipase family.

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.[2][3]

Diagnostic importance[edit]

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.[4]

See also[edit]

  • Orlistat (a pancreatic lipase inhibitor marketed as an anti-obesity medication)

References[edit]

  1. ^ PDB 1LPB; Egloff MP, Marguet F, Buono G, Verger R, Cambillau C, van Tilbeurgh H (March 1995). "The 2.46 Å resolution structure of the pancreatic lipase-colipase complex inhibited by a C11 alkyl phosphonate". Biochemistry 34 (9): 2751–62. doi:10.1021/bi00009a003. PMID 7893686. 
  2. ^ Davis RC, Diep A, Hunziker W, Klisak I, Mohandas T, Schotz MC, Sparkes RS, Lusis AJ (December 1991). "Assignment of human pancreatic lipase gene (PNLIP) to chromosome 10q24-q26". Genomics 11 (4): 1164–6. doi:10.1016/0888-7543(91)90048-J. PMID 1783385. 
  3. ^ "Entrez Gene: pancreatic lipase". 
  4. ^ Koop H (September 1984). "Serum levels of pancreatic enzymes and their clinical significance". Clin Gastroenterol 13 (3): 739–61. PMID 6207965. 

Further reading[edit]