G Bengtsson-Olivecrona

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Chylomicron catabolism is known to be initiated by the enzyme lipoprotein lipase (triacylglycero-protein acylhydrolase, EC 3.1.1.34). Chylomicron remnants, produced by lipolysis, are rapidly taken up by the liver via an apolipoprotein E (apoE)-mediated, receptor-dependent process. The low density lipoprotein (LDL) receptor-related protein (LRP) has been(More)
Lipoprotein lipase (LPL) catalyzes the flux-generating step in transport of fatty acids from lipoprotein triacylglycerols into tissues for use in metabolic reactions. In vitro studies have shown that fatty acids can bind to the enzyme and impede its other interactions. In this study we have searched for evidence of fatty acid control of LPL in vivo by rapid(More)
Lipoprotein lipase and hepatic lipase were measured in rat plasma using specific antisera. Mean values for lipoprotein lipase in adult rats were 1.8-3.6 mU/ml, depending on sex and nutritional state. Values for hepatic lipase were about three times higher. Lipoprotein lipase activity in plasma of newborn rats was 2-4-times higher than in adults. In(More)
To explore how enzyme affinities and enzyme activities regulate hydrolysis of water-insoluble substrates, we compared hydrolysis of phospholipid-stabilized emulsions of medium-chain (MCT) versus long-chain triacylglycerols (LCT). Because substrate solubility at the emulsion surface might modulate rates of hydrolysis, the ability of egg yolk(More)
This study was designed to further ascertain the presence in plasma of lipoprotein lipase (LPL) bound to circulating lipoproteins. Lipoprotein lipase mass and activity values in preheparin plasma from 20 volunteers were 69.8 +/- 6.6 ng.ml-1 and 1.54 +/- 0.15 mU.ml-1, respectively, and no significant correlation between mass and activity was observed.(More)
We have studied the binding and metabolism of 125I-labeled bovine lipoprotein lipase (LPL) by use of isolated, perfused rat livers. Our data suggest the presence of two types of binding sites, i.e., heparin-sensitive sites that bind primarily the catalytically active form of the lipase and are present at the endothelium in all blood vessels and(More)
Treatment of bovine lipoprotein lipase (LPL) with chymotrypsin results in cleavage between residues Phe390-Ser391 and between Trp392-Ser393, indicating that this region is exposed in the native conformation of LPL. Two main fragments are generated, one large including the amino-terminus (chymotrypsin-truncated LPL = c-LPL) and one small, carboxy-terminal(More)
In this study, we have investigated the effects of alimentary lipemia in 15 normotriglyceridemic individuals on high density lipoproteins2 (HDL2) with respect to structure, composition, and substrate efficacy for hepatic lipase in vitro. In the study subjects, HDL2 levels ranged widely from 4.7 to 151.7 mg/dl plasma. HDL2 were isolated in the postabsorptive(More)
To determine whether an apolipoprotein-free artificial triacylglycerol emulsion can substitute for VLDL in studying cholesterol ester-triacylglycerol exchange processes between triacylglycerol-rich lipoproteins and cholesterol ester-rich lipoproteins, we used Intralipid to modify human plasma LDL. Intralipid was incubated with LDL in the presence of(More)
Rats were injected intravenously with 125I-labeled bovine lipoprotein lipase. The lipase disappeared within minutes from the blood due to uptake both in the liver (about 50% of the injected dose) and in extrahepatic tissues. Lipase enzyme activity disappeared in parallel to the 125I radioactivity. Thus, there was no inactivation of lipase in the circulating(More)