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Lipase

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Title: Lipase  
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Subject: Sphincter of Oddi dysfunction, Triglyceride, R.EcoRII, Human digestive system, Amylase
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Lipase

A computer-generated image of a type of pancreatic lipase (PLRP2) from the guinea pig. PDB 1GPL.

A lipase is an enzyme that catalyzes the hydrolysis of fats (lipids).[1] Lipases are a subclass of the esterases.

Lipases perform essential roles in the Genes encoding lipases are even present in certain viruses.[2][3]

Most lipases act at a specific position on the glycerol backbone of lipid substrate (A1, A2 or A3)(small intestine). For example, human pancreatic lipase (HPL),[4] which is the main enzyme that breaks down dietary fats in the human digestive system, converts triglyceride substrates found in ingested oils to monoglycerides and two fatty acids.

Several other types of lipase activities exist in nature, such as phospholipases [5] and sphingomyelinases,[6] however these are usually treated separately from "conventional" lipases.

Some lipases are expressed and secreted by pathogenic organisms during the infection. In particular, Candida albicans has a large number of different lipases, possibly reflecting broad lipolytic activity, which may contribute to the persistence and virulence of C. albicans in human tissue.[7]

Contents

  • Structure and catalytic mechanism 1
  • Physiological distribution 2
  • Human lipases 3
  • Industrial uses 4
  • Diagnostic use 5
  • Additional images 6
  • See also 7
  • References 8
  • External links 9

Structure and catalytic mechanism

Although a diverse array of genetically distinct lipase enzymes are found in nature, and represent several types of protein folds and catalytic mechanisms, most are built on an alpha/beta hydrolase fold[8][9][10] (see image[11]) and employ a chymotrypsin-like hydrolysis mechanism involving a serine nucleophile, an acid residue (usually aspartic acid), and a histidine.[12][13]

Physiological distribution

Lipases are involved in diverse biological processes ranging from routine metabolism of dietary triglycerides to cell signaling[14] and inflammation.[15] Thus, some lipase activities are confined to specific compartments within cells while others work in extracellular spaces.

  • In the example of lysosome.
  • Other lipase enzymes, such as pancreatic lipases, are secreted into extracellular spaces where they serve to process dietary lipids into more simple forms that can be more easily absorbed and transported throughout the body.
  • Fungi and bacteria may secrete lipases to facilitate nutrient absorption from the external medium (or in examples of pathogenic microbes, to promote invasion of a new host).
  • Certain wasp and bee venoms contain phospholipases that enhance the "biological payload" of injury and inflammation delivered by a sting.

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 bsdl 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.[17]
lysosomal lipase LIPA interior space of 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.[18]
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.[19][20]
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.[21][22] -
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.

Industrial uses

Lipases 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[23] in alternative energy strategies to convert vegetable oil into fuel.[24][25]High enzyme activity lipase can replace traditional catalyst in processing biodiesel, this enzyme is more environmental and safe. Industrial application of lipases requires process intensification for continuous processing using tools like continuous flow microreactors at small scale.[26] [27] Lipases are generally animal sourced, but can also be sourced microbially.

Diagnostic use

Blood tests for lipase may be used to help investigate and diagnose acute pancreatitis and other disorders of the pancreas.[28] Measured serum lipase values may vary depending on the method of analysis.

Additional images

See also

References

  1. ^ Svendsen A (2000). "Lipase protein engineering". Biochim Biophys Acta 1543 (2): 223–228.  
  2. ^ Afonso C, Tulman E, Lu Z, Oma E, Kutish G, Rock D (1999). "The Genome of Melanoplus sanguinipes Entomologists". J Virol 73 (1): 533–52.  
  3. ^ 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 Virol 83 (Pt 5): 973–8.  
  4. ^ Winkler FK, D'Arcy A, and W Hunziker (1990). "Structure of human pancreatic lipase". Nature 343 (6260): 771–774.  
  5. ^ Diaz, B.L., and J. P. Arm. (2003). "Phospholipase A(2)". Prostaglandins Leukot Essent Fatty Acids 2–3 (2–3): 87–97.  
  6. ^ Goñi F, Alonso A (2002). "Sphingomyelinases: enzymology and membrane activity". FEBS Lett 531 (1): 38–46.  
  7. ^ Hube B, Stehr F, Bossenz M, Mazur A, Kretschmar M, Schafer W (2000). "Secreted lipases of Candida albicans: cloning, characterisation and expression analysis of a new gene family with at least ten members". Arch. Microbiol. 174 (5): 362–374.  
  8. ^ Winkler FK, D'Arcy A, and W Hunziker (1990). "Structure of human boob pancreatic lipase". Nature 343 (6260): 771–774.  
  9. ^ Schrag J, Cygler M (1997). "Lipases and  
  10. ^ Egmond, M. R., and C. J. van Bemmel (1997). "Impact of Structural Information on Understanding of Lipolytic Function". Methods Enzymol. Methods in Enzymology 284: 119–129.  
  11. ^ 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". Structure 4 (11): 1363–74.  
  12. ^ 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". Nature 343 (6260): 767–70.  
  13. ^ Lowe ME (1992). "The catalytic site residues and interfacial binding of human pancreatic lipase". J Biol Chem 267 (24): 17069–73.  
  14. ^ Spiegel S, Foster D, and R Kolesnick (1996). "Signal transduction through lipid second messengers". Current Opinion in Cell Biology 8 (2): 159–67.  
  15. ^ 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 Chem 270 (43): 25481–7.  
  16. ^ Genetic Code of Dandruff Cracked - BBC News
  17. ^ Lowe ME (2002). "The triglyceride lipases of the pancreas". J Lipid Res 43 (12): 2007–16.  
  18. ^ Omim - Wolman Disease
  19. ^ Familial lipoprotein lipase deficiency - Genetics Home Reference
  20. ^ Gilbert B, Rouis M, Griglio S, de Lumley L, Laplaud P (2001). "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 Genet 44 (1): 25–32.  
  21. ^ 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 Eng 11 (2): 135–42.  
  22. ^ 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 Acta 1387 (1–2): 331–41.  
  23. ^ Guo Z, Xu X (2005). "New opportunity for enzymatic modification of fats and oils with industrial potentials". Org Biomol Chem 3 (14): 2615–9.  
  24. ^ Gupta R, Gupta N, Rathi P (2004). "Bacterial lipases: an overview of production, purification and biochemical properties". Appl Microbiol Biotechnol 64 (6): 763–81.  
  25. ^ 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 J 8 (1): 39–43.  
  26. ^ Bhangale, Atul. "Enzyme-Catalyzed Polymerization of End-Functionalized Polymers in a Microreactor". Macromolecules.  
  27. ^ Bhangale, Atul; Santanu kundu. "Continuous Flow Enzyme-Catalyzed Polymerization in a Microreactor". JACS.  
  28. ^ "Lipase - TheTest". Lab Tests Online. Retrieved 12 May 2014. 

25. Gulzar, Bio-degradation of hydrocarbons using different bacterial and fungal species. Published in international conference on biotechnology and neurosciences. CUSAT (cochin university of science and technology), 2004

External links

3.1.1: Carboxylic ester hydrolases
3.1.2: Thioesterase
3.1.3: Phosphatase
3.1.4: Phosphodiesterase
3.1.6: Sulfatase
Nuclease (includes
deoxyribonuclease and
ribonuclease)
3.1.11-16: Exonuclease
Exodeoxyribonuclease
Exoribonuclease
3.1.21-31: Endonuclease
Endodeoxyribonuclease
Endoribonuclease
either deoxy- or ribo-
Fluid/electrolytes
Acid-base
Nutrition
Endocrine
Metabolic
Cardiovascular
Digestive

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