Purification of a human post-heparin plasma triglyceride lipase

A comparison of molecular properties of hepatic triglyceride lipase and lipoprotein lipase from human post-heparin plasma.

Hepatic triglyceride lipase was isolated from human post-heparin plasma by the method of Ehnholm et al. using modifications which increased the specific activity 12-fold to approximately 3,000 mumol of free fatty acid/h/mg of protein. Lipoprotein lipase with similar specific activity was prepared from the same plasma samples using heparin and concanavalin A affinity chromatography. The molecula...

Studies of fat lipolysis by post-heparin human plasma lipoprotein lipase and by human pancreatic lipase.

Positional specificity of triglyceride lipases in post-heparin plasma.

The stereochemistry of the hydrolysis of radioactive glyceryl trioleate and glyceryl diether-monoesters by lipase activity in post-heparin plasma from man, normal and hepatectomized rats, and rat liver perfusate was determined. The following substrates were chemically synthesized and employed in albumin-Triton X-100 emulsions: 1,2 dioleoyl-3 [9,10 3H]oleoyl sn glycerol; 1,3 dioleoyl2 [l W]oleoy...

Characterization, subcellular localization, and partial purification of a heparin-released triglyceride lipase from rat liver.

Post-heparin plasma in the rat contains triglyceride lipase activity of both hepatic and extrahepatic origin. The lipase released into rat hepatic perfusate by heparin has been characterized in an assay containing Triton X-100, albumin, and [14C]triolein. Fatty acid release was linear for 120 min over a wide range of enzyme concentrations at 27” and 37”. The pH optimum was 9.5. Enzymatic activi...

Effect of estrogen on post-heparin lipolytic activity. Selective decline in hepatic triglyceride lipase.

The rise in plasma triglyceride (TG) levels associated with estrogen administration has been thought to arise from impaired clearance because of the uniform suppression of post-heparin lipolytic activity (PHLA). Recently PHLA has been shown to consist of two activities: hepatic TG lipase and extrahepatic lipoprotein lipase (LPL). To determine whether estrogen might induce a selective decline in...