Binding of β-VLDL to heparan sulfate proteoglycans requires lipoprotein lipase, whereas apoE only modulates binding affinity

The binding of β-VLDL to heparan sulfate proteoglycans (HSPG) has been reported to be stimulated by both apoE and lipoprotein lipase (LPL). In the present study we investigated the effect of the isoform and the amount of apoE per particle, as well as the role of LPL on the binding of β-VLDL to HSPG. Therefore, we isolated β-VLDL from transgenic...

Effect of apolipoprotein E variants on lipolysis of very low density lipoproteins by heparan sulphate proteoglycan-bound lipoprotein lipase

Lipoprotein lipase (LPL) is bound to heparan sulphate proteoglycans (HSPG) at the luminal surface of endothelium. It is the key enzyme involved in the hydrolysis of very low density lipoproteins (VLDL). Prior to lipolysis by LPL, the lipoproteins are considered to interact with vessel wall HSPG. Apolipoprotein (apo) E is thought to mediate this...

Nascent very-low-density lipoprotein triacylgiycerol hydrolysis by lipoprotein lipase is inhibited by apolipoprotein E in a dose-dependent manner

In the present study it was investigated whether apolipoprotein (apoE) can inhibit the lipoprotein lipase (LPL)-mediated hydrolysis of very-low-density-lipoprotein (VLDL) triacylglycerols (TAGs). Previous studies have suggested such an inhibitory role for apoE by using as a substrate for LPL either plasma VLDL or artificial TAG emulsions. To...

Lipolysis of very low density lipoproteins by heparan sulfate proteoglycan-bound lipoprotein lipase

An in vitro assay to study lipolysis of very low density lipoproteins (VLDL) by heparan sulfate proteoglycan (HSPG-bound lipoprotein lipase (LPL) was developed. Optimal conditions for VLDL lipolysis by HSPG-bound LPL were obtained by incubating plastic wells with 0.5 ug HSPG and 1.5 ug LPL, subsequently. Control experiments with heparinase...

Low density lipoprotein receptor internalizes low density and very low density lipoproteins that are bound to heparan sulfate proteoglycans via lipoprotein lipase

It has previously been shown that lipoprotein lipase (LPL) enhances the binding of low density lipoproteins (LDL) and very low density lipoproteins (VLDL) to HepG2 cells and fibroblasts, up to 80-fold. This increase in binding is LDL receptor-independent and is due to a bridging of LPL between extracellular heparan sulfate proteoglycans (HSPG)...