Lipases monoglyceride

Membrane reactor Synthesis of monoglycerides Lipase from Candida rugosa 75... 

MONOD-WYMAN-CHANGEUX MODEL MONOGLYCERIDE LIPASE MONO-ISO MECHANISMS... 

Chau L. Y. and Tai H. H. (1981). Release of arachidonate from diglyceride in human platelet requires the sequential action of a diacylglycerol lipase and a monoglyceride lipase. Biochem. Biophys. Res. Commun. 100 1688-1695. 

Dinh TP, Carpenter D, Feslien FM, Freund TF, Katona I, Sensi SF, Kathuria S, Piomelli D (2002) Brain monoglyceride lipase participating in endocannabinoid inactivation. Proc Natl Acad Sci USA 99(16) 10819-24... 

Saario SM, Savinainen JR, Laitinen JT, Jarvinen T, Niemi R (2004) Monoglyceride lipase-like enzymatic activity is responsible for hydrolysis of 2-arachidonoylglycerol in rat cerebellar membranes. Biochem Pharmacol 67(7) 1381-7... 

Enzymes that hydrolyze lysophospholipids are found in nearly all tissues and organisms. They seem to be non-specific esterases of the serine-histidine type (25) and hardly deserve the name lysophospholipase because they also hydrolyze esters other than phospholipids. They should probably be considered together with such enzymes as cholesterol esterases and monoglyceride lipases as amphiphilic carboxyl ester hydrolases. These non-specific esterases have a preference for amphiphilic (hydrophilic-lipophilic) substrates. Such an enzyme may perhaps hydrolyze lysophospholipis, monoglycerides, diglycerides, and cholesterol esters. 

Karlsson M, Contreras JA, Heilman U, Tornqvist H, Holm C (1997) cDNA cloning, tissue distribution, and identification of the catalytic triad of monoglyceride lipase. Evolutionary relationship to esterases, lysophospholipases, and haloperoxidases. J Biol Chem 272 27218-27223... 

Dinh TP, Freund TF, Piomelli D (2002) A role for monoglyceride lipase in 2-arachidonoyl-glycerol inactivation. Chem Phys Lipids 121 149-158... 

Karlsson M, Reue K, Xia YR, Lusis AJ, Langin D, Tornqvist H, Holm C (2001) Exon-intron organization and chromosomal localization of the mouse monoglyceride lipase gene. Gene 272 11-18... 

Extensive studies on the endocannabinoid system have revealed a number of cannabinergic proteins involved in the inactivation and biosynthesis of endocannabinoids. These include fatty acid amide hydrolase (FAAH) (Di Marzo et al. 1994 Gaetani et al. 2003 Piomelli et al. 1999), monoglyceride lipase (MAG) (Dinh et al. 2002), and the anandamide transporter (ANT) (Beltramo et al. 1997 Di Marzo et al. 1994 Fegley et al. 2004 Hillard et al. 1997). The above three proteins and the two cannabinoid receptors have received considerable attention and show great promise as potential targets for the development of novel medications for various conditions, including pain, immunosuppression, peripheral vascular disease, appetite enhancement or suppression, and motor disorders. 

The inactivation of 2-AG in mammals is thought to be mediated by the enzyme monoglyceride lipase (MGL). However, molecular characterisation of MGL was not driven by an interest in 2-AG but by research directed at identification of the enzymes involved in the sequential hydrolysis of stored triglycerides. A mouse cDNA encoding this enzyme was cloned and sequenced by Karlsson et al. (1997) and found to encode a 302 amino acid protein that is expressed in a wide range of tissues, including brain. Subsequently, Dinh et al. (2002) demonstrated that rat MGL catalyses hydrolysis of 2-AG when expressed in cells. Interestingly, 2-AG is... 

Figure 3. Arachidonic acid release is mediated by phospholipase A2 or phospholipase C. Arachidonic acid esterified to the sn-2 position of phospholipids can be released directly by the action of phospholipase Aj or by the sequential actions of phospholipase C, diglyceride lipase, and monoglyceride lipase.

Pancreatic carboxylester lipase, secreted by the pancreas as an active enzyme without proteolytic activation, displays broad substrate specificity and has therefore received many names in the literature carboxylesterase, bile salt-stimulated (or activated or dependent) lipase (due to its absolute requirement for bile salts to hydrolyze insoluble substrates), carboxylester lipase or hydrolase, cholesterol esterase, lysophospholipase, nonspecific lipase, and monoglyceride lipase. The IUPAC classification of the enzyme has been either EC.3.1.1.1 (carboxylester hydrolase) or EC.3.1.1.13 (cholesterolester hydrolase) (Table 2). 

Dinh, T.R, Carpenter, D., Leslie, FM., Freund, T.F, Katona, I., Sensi, S.L., Kathuria, S., and Piomelli, D. (2002) Brain monoglyceride lipase participating in endocannabinoid inactivation. Proceedings of the National Academy of Sciences of the USA 99 10819-10824. Erratum Proceedings of the National Academy of Sciences of the USA (2002) 99 13961. 

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