A lipase is a water-soluble enzyme that catalyzes the hydrolysis of ester bonds in water–insoluble, lipid substrates[1]. Lipases thus comprise a subclass of the esterases.
Lipases are ubiquitous throughout living organisms, and genes encoding lipases are even present in certain viruses. [2][3]
Most lipases act at a specific position on the glycerol backbone of a lipid substrate (A1, A2 or A3).
In the example of human pancreatic lipase (HPL)[4], which is the main enzyme responsible for breaking down fats in the human digestive system, a lipase acts to convert triglyceride substrates found in oils from food to monoglycerides and free fatty acids.
Myriad of other lipase activities exist in nature, especially when the phospholipases[5] and sphingomyelinases[6] are considered.
Some lipases work within the interior spaces of living cells to degrade lipids.
In the example of lysosomal lipase, the enzyme is confined within an organelle called the lysosome.
Other lipase enzymes, such as pancreatic lipases, are found in the spaces outside of cells and have roles in the metabolism, absorption and transport of lipids throughout the body.
The main lipases in 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
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[15].
-
lysosomal lipase
LIPA
intracellular
Also referred to as lysosomal acid lipase (LAL or LIPA) or acid cholesteryl ester hydrolase
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[19][20].
-
lingual lipase
?
digestive juice
-
-
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.
Industrial Uses
Lipases from fungi and bacteria serve important roles in human practices as ancient as yogurt and cheese fermentation. However, lipases are also being exploited as cheap and versatile catalysts to degrade lipids in more modern applications. For instance, a biotechnology company has brought recombinant lipase enzymes to market for use in applications such as baking, laundry detergents and even as biocatalysts[21] in alternative energy strategies to convert vegetable oil into fuel. [22][23]
Additional images
References
^ Svendsen A (2000). "Lipase protein engineering". Biochim Biophys Acta1543 (2): 223-228. PMID 11150608.
^ Afonso C, Tulman E, Lu Z, Oma E, Kutish G, Rock D (1999). "The genome of Melanoplus sanguinipes entomopoxvirus". J Virol73 (1): 533-52. PMID 9847359.
^ Girod A, Wobus C, Zádori Z, Ried M, Leike K, Tijssen P, Kleinschmidt J, Hallek M (2002). "The VP1 capsid protein of adeno-associated virus type 2 is carrying a phospholipase A2 domain required for virus infectivity". J Gen Virol83 (Pt 5): 973-8. PMID 11961250.
^ Winkler FK, D'Arcy A, and W Hunziker (1990). "Structure of human pancreatic lipase". Nature343 (6260): 771-774. PMID 2106079.
^ Diaz, B.L., and J. P. Arm. (2003). "Phospholipase A(2).". Prostaglandins Leukot Essent Fatty Acids2-3: 87-97. PMID 12895591.
^ Goñi F, Alonso A (2002). "Sphingomyelinases: enzymology and membrane activity". FEBS Lett531 (1): 38-46. PMID 12401200.
^ Schrag J, Cygler M. "Lipases and alpha/beta hydrolase fold". Methods Enzymol284: 85-107. PMID 9379946.
^ Winkler FK, D'Arcy A, and W Hunziker (1990). "Structure of human pancreatic lipase". Nature343 (6260): 771-774. PMID 2106079.
^ Egmond, M. R., and C. J. van Bemmel (1997). "Impact of Structural Information on Understanding of Lipolytic Function". Methods Enzymol284: 119-129. PMID 9379930.
^ Withers-Martinez C, Carriere F, Verger R, Bourgeois D, and C Cambillau (1996). "A pancreatic lipase with a phospholipase A1 activity: crystal structure of a chimeric pancreatic lipase-related protein 2 from guinea pig". Structure4 (11): 1363-74. PMID 8939760.
^ Brady, L., A. M. Brzozowski, Z. S. Derewenda, E. Dodson, G. Dodson, S. Tolley, J. P. Turkenburg, L. Christiansen, B. Huge-Jensen, L. Norskov, and et al. (1990). "A serine protease triad forms the catalytic centre of a triacylglycerol lipase.". Nature343 (6260): 767-70. PMID 2304552.
^ Lowe ME (1992). "The catalytic site residues and interfacial binding of human pancreatic lipase". J Biol Chem267 (24): 17069-73. PMID 1512245.
^ Spiegel S, Foster D, and R Kolesnick (1996). "Signal transduction through lipid second messengers". Curr Opin Cell Biol8 (2): 159-67. PMID 8791422.
^ Tjoelker LW, Eberhardt C, Unger J, Trong HL, Zimmerman GA, McIntyre TM, Stafforini DM, Prescott SM, and PW Gray (1995). "Plasma platelet-activating factor acetylhydrolase is a secreted phospholipase A2 with a catalytic triad". J Biol Chem270 (43): 25481-7. PMID 7592717.
^ Lowe ME (2002). "The triglyceride lipases of the pancreas". J Lipid Res43 (12): 2007-16. PMID 12454260.
^ Gilbert B, Rouis M, Griglio S, de Lumley L, Laplaud P. "Lipoprotein lipase (LPL) deficiency: a new patient homozygote for the preponderant mutation Gly188Glu in the human LPL gene and review of reported mutations: 75 % are clustered in exons 5 and 6". Ann Genet44 (1): 25-32. PMID 11334614.
^ Crenon I, Foglizzo E, Kerfelec B, Verine A, Pignol D, Hermoso J, Bonicel J, Chapus C (1998). "Pancreatic lipase-related protein type I: a specialized lipase or an inactive enzyme". Protein Eng11 (2): 135-42. PMID 9605548.
^ De Caro J, Carriere F, Barboni P, Giller T, Verger R, De Caro A (1998). "Pancreatic lipase-related protein 1 (PLRP1) is present in the pancreatic juice of several species". Biochim Biophys Acta1387 (1-2): 331-41. PMID 9748646.
^ Guo Z, Xu X (2005). "New opportunity for enzymatic modification of fats and oils with industrial potentials.". Org Biomol Chem3 (14): 2615-9. PMID 15999195.
^ Gupta R, Gupta N, Rathi P (2004). "Bacterial lipases: an overview of production, purification and biochemical properties". Appl Microbiol Biotechnol64 (6): 763-81. PMID 14966663.
^ Ban K, Kaieda M, Matsumoto T, Kondo A, Fukuda H (2001). "Whole cell biocatalyst for biodiesel fuel production utilizing Rhizopus oryzae cells immobilized within biomass support particles". Biochem Eng J8 (1): 39-43. PMID 11356369.
