High-Level Expression and Purification of Human Hepatic Lipase from Mammalian Cells

Through its ability to catalyze the hydrolysis of triglycerides and phospholipids, hepatic lipase (HL) has been shown to influence the metabolism of a broad range of circulating lipoproteins (1 ). HL is synthesized and secreted by hepatocytes and is found bound, through an ionic interaction with heparan sulfate proteoglycans, to the luminal surface of endothelium lining the liver sinusoids (2 ). The detection of HL catalytic activity in the ovary and adrenal gland, but not protein synthesis, suggests that HL is transported and binds specifically to these tissues as well (3 ,4 ). In addition, there is evidence to suggest that, independent of its catalytic activity, HL can act as a ligand to facilitate the uptake of remnant lipoproteins through its interaction with cell surface proteoglycans and/or cell surface receptors (5 –8 ).