Key enzyme in triglyceride metabolism (By similarity). Catalyzes the hydrolysis of triglycerides from circulating chylomicrons and very low density lipoproteins (VLDL), and thereby plays an important role in lipid clearance from the blood stream, lipid utilization and storage (By similarity). Although it has both phospholipase and triglyceride lipase activities it is primarily a triglyceride lipase with low but detectable phospholipase activity (By similarity). Mediates margination of triglyceride-rich lipoprotein particles in capillaries (By similarity). Recruited to its site of action on the luminal surface of vascular endothelium by binding to GPIHBP1 and cell surface heparan sulfate proteoglycans (By similarity). a triacylglycerol + H2O = a diacylglycerol + a fatty acid + H(+) a 1,2-diacyl-sn-glycero-3-phosphocholine + H2O = a 2-acyl-sn-glycero-3-phosphocholine + a fatty acid + H(+) 1,2,3-tri-(9Z-octadecenoyl)-glycerol + H2O = (9Z)-octadecenoate + di-(9Z)-octadecenoylglycerol + H(+) 1,2-di-(9Z-octadecenoyl)-sn-glycero-3-phosphocholine + H2O = (9Z)-octadecenoate + (9Z-octadecenoyl)-sn-glycero-3-phosphocholine + H(+) 1,2,3-tributanoylglycerol + H2O = butanoate + dibutanoylglycerol + H(+) 1,2-dihexadecanoyl-sn-glycero-3-phosphocholine + H2O = H(+) + hexadecanoate + hexadecanoyl-sn-glycero-3-phosphocholine The apolipoprotein APOC2 acts as a coactivator of LPL activity (By similarity). Ca(2+) binding promotes protein stability and formation of the active homodimer. Interaction with GPIHBP1 protects LPL against inactivation by ANGPTL4 (By similarity). Homodimer. Interacts with GPIHBP1 with 1:1 stoichiometry (By similarity). Interacts with APOC2; the interaction activates LPL activity in the presence of lipids (By similarity). Interaction with heparan sulfate proteoglycans is required to protect LPL against loss of activity. Associates with lipoprotein particles in blood plasma. Interacts with LMF1 and SEL1L; interaction with SEL1L is required to prevent aggregation of newly synthesized LPL in the endoplasmic reticulum (ER), and for normal export of LPL from the ER to the extracellular space (By similarity). Interacts with SORL1; SORL1 acts as a sorting receptor, promoting LPL localization to endosomes and later to lysosomes, leading to degradation of newly synthesized LPL (By similarity). Newly synthesized LPL binds to cell surface heparan proteoglycans and is then released by heparanase. Subsequently, it becomes attached to heparan proteoglycan on endothelial cells. Locates to the plasma membrane of microvilli of hepatocytes with triglyceride-rich lipoproteins (TRL). Some of the bound LPL is then internalized and located inside non-coated endocytic vesicles. Highest levels in the spinal cord. Tyrosine nitration after lipopolysaccharide (LPS) challenge down-regulates the lipase activity. Belongs to the AB hydrolase superfamily. Lipase family.