Lipase Triacylglycerol Acyl Hydrolase

Lipases (triacylglycerol acyl hydrolases, EC 3.1.1.3), have been well established as a valuable catalyst in organic synthesis.12 They are usually distinguished from carboxyl esterases (EC 3.1.1.1) by their substrate spectra, i.e. esterases prefer water soluble substrates and lipases show significantly higher activity towards their natural substrates,... 

Contrary to these processes, enzyme-catalyzed reactions using lipases have proven to be an interesting alternative for industrial-scale biodiesel production in order to reduce production costs. Lipases (triacylglycerol acyl-hydrolases, E.C. 3.1.1.3.) are powerful tools that can catalyze not only hydrolysis but also various synthetic reactions including esterification and transesterification. 

This enzyme (triacylglycerol acyl-hydrolase) has a molecular mass of approximately 42 kDa (Hide, Chan, and Li 1992) and a short half-life of about 1-3 h in dogs. Pancreatic lipase is secreted in its active form, and this activity is enhanced by colipase and bile salts the enzyme hydrolyzes triglycerides to monoglycerides. Other lipases— phospholipase a, phospholipase b, and cholesterol ester hydrolase—are also secreted by the pancreas. 

LONG-CHAIN TRIACYLGLYCEROL ACYL HYDROLASE (LIPASE) ACTIVITY IN WHEAT GRAIN... 

The breakdown of triacylglycerol is catalysed by lipases. A large number of such enzymes have been purified from animals, plants and microbes (cf. Brockerhoff and Jensen, 1974). It should be noted that the term lipase is frequently misused. A true lipase is one which attacks triacylglycerols and acts only at an oil-water interface. This definition therefore excludes enzymes acting on water-soluble esters (esterases) or those preferentially hydrolysing other lipids (acyl hydrolases). 

Although bacteria do not store energy as triacylglycerol, a number of bacterial lipases have been discovered and studied. An extensive review of microbial lipases (and esterases) has been made by Lawrence (1967). It should be emphasized also that many of the microbial Upases (e.g. the widely studied Rhizopus arrhizus enzyme) are, in fact, acyl hydrolases. 

True lipases from plants will hydrolyze these partial glycerides, but other enzymes that attack monoacylglycerols (but not triacylglycerols) have been described. However, in most cases the full substrate specificities of these enzymes have not been studied. In one case a lipolytic acyl hydrolase from potato tubers was shown to hydrolyze mono- and diacylglycerols in addition to a range of polar lipids. Thus, to avoid introducing a class of hydrolytic... 

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