In enzymology, a galactolipase (EC 18.104.22.168) is an enzyme that catalyzes the chemical reaction 1,2-diacyl-3-beta-D-galactosyl-sn-glycerol + 2 H2O=3-beta-D-galactosyl-sn-glycerol + 2 carboxylates Thus, the two substrates of this enzyme are 1,2-diacyl-3-beta-D-galactosyl-sn-glycerol and H2O, whereas its two products are 3-beta-D-galactosyl-sn-glycerol and carboxylate. This enzyme belongs to the family of hydrolases, specifically those acting on carboxylic ester bonds. The systematic name of this enzyme class is 1,2-diacyl-3-beta-D-galactosyl-sn-glycerol acylhydrolase. Other names in common use include galactolipid lipase, polygalactolipase, and galactolipid acylhydrolase. This enzyme participates in glycerolipid metabolism.
Lipase with broad substrate specificity. Galactolipase can hydrolyze both phospholipids and galactolipids. Galactolipase acts preferentially on monoglycerides, phospholipids and galactolipids. Galactolipase contributes to milk fat hydrolysis.
Galactolipase has a pancreatic triacylglycerol lipase activity
Galactolipase is involved in the digestion of galactolipids, the most abundant lipids occurring in plant cells
Galactolipase can hydrolyze triolein emulsified in bile salt micelles in contrast to previous reports
Galactolipase acts preferentially on substrates forming monomers or small aggregates (micelles) dispersed in solution like monoglycerides, phospholipids and galactolipids
Galactolipase is found to express galactolipase activity, and it is assumed to be the main enzyme involved in the digestion of these common vegetable lipids in the gastrointestinal tract
Galactolipase can contribute to fat digestion during early infancy
Galactolipase may not function as a triglyceride lipase
unlike PNLIP, the activity of Galactolipase is not restored by the addition of another pancreatic protein, colipase
Galactolipase's activity was comparable with the activity of CEL, another lipase that contributes to dietary fat digestion in newborns