Apolipoproteins regulate the kinetics of endothelial lipase-mediated hydrolysis of phospholipids in reconstituted high-density lipoproteins

Biochemistry
Daniela CaiazzaK A Rye

Abstract

Endothelial lipase (EL) is a newly identified member of the triglyceride lipase gene family that hydrolyzes high-density lipoprotein (HDL) phospholipids. This study investigates the ability of the major apolipoproteins of rHDL to regulate the kinetics of EL-mediated phospholipid hydrolysis in well-characterized, homogeneous preparations of spherical rHDL. The rHDL contained either apoA-I as the only apolipoprotein, (A-I)rHDL, apoA-II as the only apolipoprotein, (A-II)rHDL, or apoA-I as well as apoA-II, (A-I/A-II)rHDL. The rHDL were comparable in terms of size and lipid composition and contained cholesteryl esters (CE) as their sole core lipid. Phospholipid hydrolysis was quantitated as the mass of nonesterified fatty acids (NEFA) released from the rHDL during incubation with EL. The V(max) of phospholipid hydrolysis for (A-I/A-II)rHDL [391.9 +/- 12.9 nmol of NEFA formed (mL of EL)(-1) h(-1)] was greater than (A-I)rHDL [152.8 +/- 4.7 nmol of NEFA formed (mL of EL)(-1) h(-1)]. The energy of activation (E(a)) for the hydrolysis reactions was calculated to be 52.1 and 34.8 kJ mol(-1) for (A-I)rHDL and (A-I/A-II)rHDL, respectively. Minimal phospholipid hydrolysis was observed for the (A-II)rHDL. Kinetic analysis showed that EL has a...Continue Reading

References

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Feb 6, 2003·The Journal of Clinical Investigation·Tatsuro IshidaThomas Quertermous

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Citations

Nov 27, 2008·Journal of Lipid Research·Kerry-Anne RyePhilip J Barter
Feb 25, 2006·The Canadian Journal of Cardiology·Marie-Eve Paradis, Benoit Lamarche
Sep 1, 2005·Aesthetic Surgery Journal·Diane Irvine Duncan, Franz Hasengschwandtner
Nov 18, 2006·Clinics in Laboratory Medicine·G Russell WarnickCleland C Landolt
Jan 5, 2014·Circulation Research·Kerry-Anne Rye, Philip J Barter
Dec 28, 2007·The Journal of Biological Chemistry·Lawrence W CastellaniAldons J Lusis
Dec 27, 2013·Journal of Atherosclerosis and Thrombosis·Li SunKen-ichi Hirata
Jun 21, 2008·Journal of Biomolecular Screening·Paul M KellerBenjamin Schwartz

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