Targeting of Porcine Pancreatic Phospholipase A2 to Human Platelets
- 1 May 1996
- journal article
- Published by Wiley in European Journal of Biochemistry
- Vol. 238 (1), 70-76
- https://doi.org/10.1111/j.1432-1033.1996.0070q.x
Abstract
In the present study we prepared by chemical modification a series of porcine pancreatic phospholipase A2 (PLA) derivatives, that bind to the activated glycoprotein (GP) IIb/IIIa complex and hydrolyse phospholipids in the outer leaflet of the platelet membrane. To the native enzyme, an RGD-containing peptide was coupled to introduce affinity for GPIIb/IIIa in combination with lauric acid to improve binding to the membrane. As controls, derivatives containing only one of these modifications were prepared. Acylation of the enzyme improved the affinity for densely packed phospholipids, as deduced by kinetic analyses. After stimulation of platelets, the RGD-containing PLAs bound to GPIIb/IIIa since GRGDS peptide and a monoclonal antibody against the complex interfered with binding. No binding was found with native PLA. The binding seen with lauric acid PLA was not mediated by GPIIb/IIIa. All modified PLAs induced 1-3% hydrolysis of [3H]arachidonic-acid-labelled phospholipids in resting platelets. After activation with alpha-thrombin, hydrolysis increased to 17%, corresponding to about 90% of [3H]arachidonate-labelled phospholipids in the outer leaflet of the plasma membrane. RGD-containing PLAs were more active than lauroyl PLA, and their activity was mediated via GPIIb/IIIa since GRGDS inhibited release of [3H]arachidonic acid. Acylation of the RGD-containing PLAs did not further improve the hydrolytic properties. We conclude that chemical modification of PLA leads to a targetted hydrolytic action and could be a basis for the design of enzymes that specifically destroy activated platelets.Keywords
This publication has 36 references indexed in Scilit:
- Acylation of porcine pancreatic phospholipase A2 influences penetration and substrate head‐group binding, depending on the position of the acylated lysine in the enzyme moleculeEuropean Journal of Biochemistry, 1993
- Integrins: Versatility, modulation, and signaling in cell adhesionCell, 1992
- Transbilayer movement of phospholipids in red cell and platelet membranesBiochimica et Biophysica Acta (BBA) - Reviews on Biomembranes, 1991
- Competitive inhibition of lipolytic enzymes. I. A kinetic model applicable to water-insoluble competitive inhibitorsBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, 1990
- Site-specific .epsilon.-amino monoacylation of pancreatic phospholipase A2. 1. Preparation and propertiesBiochemistry, 1988
- Changes in membrane phospholipid distribution during platelet activationBiochimica et Biophysica Acta (BBA) - Biomembranes, 1983
- Semisynthesis of phospholipase A2. Preparation and properties of arginine-6 bovine pancreatic phospholipase A2Biochemistry, 1981
- Metabolism of [14C]arachidonic acid by human plateletsBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, 1976
- Relation between various phospholipase actions on human red cell membranes and the interfacial phospholipid pressure in monolayersBiochimica et Biophysica Acta (BBA) - Biomembranes, 1975
- Application of mass spectrometry to the analysis of proteins containing a N‐terminal pyroglutamic acid residueFEBS Letters, 1969