title: Acidic "peptidophospholipids", a new class of hapten-bearing cell surface modifying reagents.
abstract: Covalent coupling of glutamyl-glutamic acid to the amino group of ether-phosphatidylethanolamine (EPE) yields an acidic "peptidophospholipid" (Glu2-EPE) which is water-soluble above pH 7.0 and stable to phospholipase A. The terminal amino group of Glu2-EPE is free for coupling with amino-reactive determinants. We describe the synthesis of various hapten-substituted peptidophospholipids as well as of an intermediate compound, coupled with the heterobifunctional reagent 3-(2'-pyridyl)-dithiopropionic acid N-hydroxysuccinimide ester. The latter derivative allows binding to sulfhydryl-containing molecules, e.g. peptides or proteins. So far, beef and pig insulin as well as trinitrophenyl-substituted ribonuclease A have thus been linked to Glu2-EPE. All derivatives of Glu2-EPE are water-soluble at physiological pH and readily adsorb to cell surfaces from aq. solution. Binding to cells is fast, stable and "non-toxic" over a wide range of concns. The adsorbed determinants are accessible to specific antibodies and facilitate complement-mediated cell lysis. Glu2-EPE thus appears to be a universal carrier molecule for fast, simple and mild modification of cells with foreign determinants, e.g. for Jerne plaque assays.
mesh_terms: D000818:Animals; D000921:Antibody-Producing Cells / Q000276:immunology; D002462:Cell Membrane / Q000276:immunology; D002478:Cells, Cultured; D002645:Chickens; D000939:Epitopes / Q000276:immunology; D004912:Erythrocytes / Q000276:immunology; D006241:Haptens / Q000276:immunology*; D006462:Hemolytic Plaque Technique; D007330:Insulin Antibodies / Q000096:biosynthesis; D051379:Mice; D010714:Phosphatidylethanolamines / Q000138:chemical synthesis / Q000276:immunology*; D010742:Phospholipid Ethers; D012756:Sheep; D012995:Solubility
chemical_list: D000939:Epitopes; D006241:Haptens; D007330:Insulin Antibodies; D010714:Phosphatidylethanolamines; D010742:Phospholipid Ethers; C043080:diglutamylphosphatidylethanolamine dihexadecyl ether