Lipoprotein lipase (LPL) is the key enzyme that mediates the catabolism of triglycerides in chylomicrons and very low density lipoproteins. The hydrolysis of triglycerides by LPL results in the generation of glycerol and fatty free acids. LPL is primarily synthesized by adipocytes, muscle cells and macrophages. Lipase is bound on the luminal surface of capillary endothelial cells through its interaction with heparan sulfate proteoglycan chains. The activity of LPL is stimulated in the presence of its cofactor, apoprotein C-II. It also acts as a ligand in binding lipoproteins to cell surface and receptors. The enzyme is a non-covalent homodimer. Amino-terminal domain has the catalytic triad which consists of Ser132-Asp156-His241. Various factors regulate LPL activity. Mediators activating enzyme activity are insulin, thyroxin, prolactin. Mediators inhibiting enzyme activity are cytokines, prostaglandins, oxidised LDL. Pancreatic, hepatic lipase and LPL are members of the human lipase gene family. The LPL gene is located on chromosome 8p22. Almost 100 naturally occuring mutations in the LPL gene have been described; they have been linked toLPL deficiency, hypertriglyceridaemia, reduced levels ofHDL and triglycerides. Abnormalities in LPL function have been found to be associated with a number of pathologies including atherosclerosis, obesity, Alzheimer’s disease, chylomicronaemia, dyslipidaemia associated with diabetes, insulin resistance etc.

        Key words: lipoprotein lipase, triglycerides, chylomicrons, very low density lipoproteins, catalytic triad, deficiency, atherosclerosis.