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Evidence that hepatic lipase and endothelial lipase have different substrate specificities for high-density lipoprotein phospholipids

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dc.contributor.authorDuong, M.
dc.contributor.authorPsaltis, M.
dc.contributor.authorRader, D.
dc.contributor.authorMarchadier, D.
dc.contributor.authorBarter, P.
dc.contributor.authorRye, K.
dc.date.issued2003
dc.description.abstractHepatic lipase (HL) and endothelial lipase (EL) are both members of the triglyceride lipase gene family. HL hydrolyzes phospholipids and triglycerides in triglyceride-rich lipoproteins and high-density lipoproteins (HDL). EL hydrolyzes HDL phospholipids and has low triglyceride lipase activity. The aim of this study was to determine if HL and EL hydrolyze different HDL phospholipids and whether HDL phospholipid composition regulates the interaction of EL and HL with the particle surface. Spherical, reconstituted HDL (rHDL) containing either 1-palmitoyl-2-oleoylphosphatidylcholine (POPC), 1-palmitoyl-2-linoleoylphosphatidylcholine (PLPC), 1-palmitoyl-2-arachidonylphosphatidylcholine (PAPC), or 1-palmitoyl-2-docosahexanoylphosphatidylcholine (PDPC) as the only phospholipid, apolipoprotein A-I as the only apolipoprotein, and either cholesteryl esters (CE) only or mixtures of CE and triolein (TO) in their core were prepared. The rHDL were similar in size and had comparable core lipid/apoA-I molar ratios. The CE-containing rHDL were used to determine the kinetics of HL- and EL-mediated phospholipid hydrolysis. For HL the V(max) of phospholipid hydrolysis for (POPC)rHDL > (PLPC)rHDL approximately (PDPC)rHDL > (PAPC)rHDL, while the K(m)(app) for (POPC)rHDL > (PDPC)rHDL > (PLPC)rHDL > (PAPC)rHDL. For EL the V(max) for (PDPC)rHDL > (PAPC)rHDL > (PLPC)rHDL approximately (POPC)rHDL, while the K(m)(app) for (PAPC)rHDL approximately (PLPC)rHDL > (POPC)rHDL > (PDPC)rHDL. The kinetics of EL- and HL-mediated TO hydrolysis was determined using rHDL that contained TO in their core. For HL the V(max) of TO hydrolysis for (PLPC)rHDL > (POPC)rHDL > (PAPC)rHDL > (PDPC)rHDL, while the K(m)(app) for (PLPC)rHDL > (POPC)rHDL approximately (PAPC)rHDL > (PDPC)rHDL. For EL the V(max) and K(m)(app) for (PAPC)rHDL > (PDPC)rHDL > (PLPC)rHDL > (POPC)rHDL. These results establish that EL and HL have different substrate specificities for rHDL phospholipids and that their interactions with the rHDL surface are regulated by phospholipids.
dc.identifier.citationBiochemistry, 2003; 42(46):13778-13785
dc.identifier.doi10.1021/bi034990n
dc.identifier.issn0006-2960
dc.identifier.issn1520-4995
dc.identifier.orcidDuong, M. [0000-0002-9542-1187]
dc.identifier.urihttp://hdl.handle.net/2440/9295
dc.language.isoen
dc.publisherAmer Chemical Soc
dc.source.urihttps://doi.org/10.1021/bi034990n
dc.subjectLiver
dc.subjectCOS Cells
dc.subjectAnimals
dc.subjectHumans
dc.subjectTritium
dc.subjectCholesterol Esters
dc.subjectLipase
dc.subjectTriolein
dc.subjectTriglycerides
dc.subjectLipoproteins, HDL
dc.subjectPhospholipids
dc.subjectApolipoprotein A-I
dc.subjectSubstrate Specificity
dc.subjectHydrolysis
dc.subjectKinetics
dc.subjectCatalysis
dc.titleEvidence that hepatic lipase and endothelial lipase have different substrate specificities for high-density lipoprotein phospholipids
dc.typeJournal article
pubs.publication-statusPublished

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