MetaCyc Reaction:

Superclasses: Reactions Classified By Conversion Type Simple Reactions Chemical Reactions
Reactions Classified By Substrate Small-Molecule Reactions

EC Number: ,

Enzymes and Genes:
triacylglycerol lipase Inferred from experiment : TGL3 ( Saccharomyces cerevisiae )
hormone-sensitive lipase Inferred from experiment : LIPE ( Homo sapiens )

In Pathway: triacylglycerol degradation

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.

Most BioCyc compounds have been protonated to a reference pH value of 7.3, and some reactions have been computationally balanced for hydrogen by adding free protons. Please see the PGDB Concepts Guide for more information.

Mass balance status: Balanced.

Enzyme Commission Primary Name for lipoprotein lipase

Enzyme Commission Synonyms for clearing factor lipase, diacylglycerol lipase, postheparin esterase, diglyceride lipase, postheparin lipase, diacylglycerol hydrolase, lipemia-clearing factor

Enzyme Commission Primary Name for hormone-sensitive lipase

Enzyme Commission Synonyms for HSL

Standard Gibbs Free Energy (ΔrG in kcal/mol): -13.038223 Inferred by computational analysis [Latendresse13]

Enzyme Commission Summary for
Hydrolyses triacylglycerols in chylomicrons and low-density lipoproteins. Also hydrolyses diacylglycerol.

Enzyme Commission Summary for
This enzyme is a serine hydrolase. Compared with other lipases, hormone-sensitive lipase has a uniquely broad substrate specificity. It hydrolyses all acylglycerols (triacylglycerol, diacylglycerol and monoacylglycerol) as well as cholesteryl esters, steroid fatty acid esters , retinyl esters and p-nitrophenyl esters. It exhibits a preference for the 1- or 3-ester bond of its acylglycerol substrate compared with the 2-ester bond. The enzyme shows little preference for the fatty acids in the triacylglycerol, although there is some increase in activity with decreasing chain length. The enzyme activity is increased in response to hormones that elevate intracellular levels of cAMP.

Citations: [Holm00, Fredrikson81, VAUGHAN64, Osterlund96, Egelrud73, Fielding70, Greten70, Morley72, NilssonEhle71, Wei97a, Lee88a, Tsujita89, Yeaman04]

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

Instance reaction of [a triglyceride + H2O → a 1,2-diglyceride + a fatty acid + H+] (
i4: tributyrin + H2O → 1,2-dibutyrin + butanoate + H+ (

Instance reaction of [an acyl-CoA + a 1-acyl 2-lyso-phosphatidylcholine ↔ a phosphatidylcholine + coenzyme A] (
i8: palmitoyl-CoA + 1-16:0-2-lysophosphatidylcholine ↔ 1,2-dipalmitoyl-phosphatidylcholine + coenzyme A (

Instance reaction of [a phosphatidylcholine + H2O → a 1-acyl 2-lyso-phosphatidylcholine + a long-chain fatty acid + H+] (
i5: 1,2-dipalmitoyl-phosphatidylcholine + H2O → 1-16:0-2-lysophosphatidylcholine + palmitate + H+ (

Instance reaction of [an L-1-phosphatidylethanolamine[periplasmic space] + H2O[periplasmic space] → a fatty acid[periplasmic space] + a 1-acyl 2-lyso-phosphatidylethanolamine[periplasmic space] + H+[periplasmic space]] (
i3: 1-18:1-2-18:1-phosphatidylethanolamine + H2O → 1-18:1-lysophosphatidylethanolamine + oleate + H+ (

Instance reactions of [a steryl-ester + H2O → a fatty acid + a sterol + H+] (
i6: ergosteryl oleate + H2O → ergosterol + oleate + H+ (

i7: lanosteryl oleate + H2O → lanosterol + oleate + H+ (

Unification Links: KEGG:R05209 , Rhea:18761

Relationship Links: BRENDA:EC: , BRENDA:EC: , ENZYME:EC: , ENZYME:EC: , IUBMB-ExplorEnz:EC: , IUBMB-ExplorEnz:EC: , UniProt:RELATED-TO:P06858 , UniProt:RELATED-TO:P11152 , UniProt:RELATED-TO:P11153 , UniProt:RELATED-TO:P11602 , UniProt:RELATED-TO:P49923 , UniProt:RELATED-TO:Q06000 , UniProt:RELATED-TO:Q29524


Egelrud73: Egelrud T, Olivecrona T (1973). "Purified bovine milk (lipoprotein) lipase: activity against lipid substrates in the absence of exogenous serum factors." Biochim Biophys Acta 306(1);115-27. PMID: 4703566

Fielding70: Fielding CJ (1970). "Human lipoprotein lipase. I. Purification and substrate specificity." Biochim Biophys Acta 206(1);109-17. PMID: 5441398

Fredrikson81: Fredrikson G, Stralfors P, Nilsson NO, Belfrage P (1981). "Hormone-sensitive lipase of rat adipose tissue. Purification and some properties." J Biol Chem 256(12);6311-20. PMID: 7240206

Greten70: Greten H, Levy RI, Fales H, Fredrickson DS (1970). "Hydrolysis of diglyceride and glyceryl monoester diethers with "lipoprotein lipase"." Biochim Biophys Acta 210(1);39-45. PMID: 5466051

Holm00: Holm C, Osterlund T, Laurell H, Contreras JA (2000). "Molecular mechanisms regulating hormone-sensitive lipase and lipolysis." Annu Rev Nutr 20;365-93. PMID: 10940339

Latendresse13: Latendresse M. (2013). "Computing Gibbs Free Energy of Compounds and Reactions in MetaCyc."

Lee88a: Lee FT, Adams JB, Garton AJ, Yeaman SJ (1988). "Hormone-sensitive lipase is involved in the hydrolysis of lipoidal derivatives of estrogens and other steroid hormones." Biochim Biophys Acta 963(2);258-64. PMID: 3196730

Morley72: Morley N, Kuksis A (1972). "Positional specificity of lipoprotein lipase." J Biol Chem 247(20);6389-93. PMID: 5076762

NilssonEhle71: Nilsson-Ehle P, Belfrage P, Borgstrom B (1971). "Purified human lipoprotein lipase: positional specificity." Biochim Biophys Acta 248(1);114-20. PMID: 5168777

Osterlund96: Osterlund T, Danielsson B, Degerman E, Contreras JA, Edgren G, Davis RC, Schotz MC, Holm C (1996). "Domain-structure analysis of recombinant rat hormone-sensitive lipase." Biochem J 319 ( Pt 2);411-20. PMID: 8912675

Tsujita89: Tsujita T, Ninomiya H, Okuda H (1989). "p-nitrophenyl butyrate hydrolyzing activity of hormone-sensitive lipase from bovine adipose tissue." J Lipid Res 30(7);997-1004. PMID: 2794798


Wei97a: Wei S, Lai K, Patel S, Piantedosi R, Shen H, Colantuoni V, Kraemer FB, Blaner WS (1997). "Retinyl ester hydrolysis and retinol efflux from BFC-1beta adipocytes." J Biol Chem 272(22);14159-65. PMID: 9162045

Yeaman04: Yeaman SJ (2004). "Hormone-sensitive lipase--new roles for an old enzyme." Biochem J 379(Pt 1);11-22. PMID: 14725507

Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 19.0 on Fri Mar 27, 2015, BIOCYC13A.