FIGURE 3.

mAb#15 selectively binds 1-oleoyl-phosphatidylcholine. A, binding of mAb#15 to phosphatidylcholine standards with different acyl chain compositions was measured by ELISA (red, DOPC; purple, OPPC; green, POPC; black, DPPC; blue, distearoylphosphatidylcholine; gray, dilinoleoylphosphatidylcholine). B, binding of mAb#15 to 1-oleoyl-lyso-PC in liposome was examined by a flow cytometer (green, 80% DPPC, 20% cholesterol liposome (the base liposome) with mAb#15; blue, the base liposome plus 10% 1-palmitoyl-2-lyso-PC with mAb#15; black, the base liposome plus 10% 1-oleoyl-2-lyso-PC with no mAb#15; red, the base liposome plus 10% 1-oleoyl-2-lyso-PC with mAb#15. C, binding of mAb#15 to dioleoyl phospholipid standards with different headgroups or to sphingomyelin was measured by ELISA (red, DOPC; black, DOPE; blue, dioleoylphosphatidylinositol; green, dioleoylphosphatidylserine; yellow, sphingomyelin). D, mAb#15 binding to a panel of phospholipids (100 pmol each) was evaluated with the lipids spotted on a membrane. LPA, lysophosphatidic acid; LPC, lysophosphatidylcholine; PI, phosphatidylinositol; PI(3)P, phosphatidylinositol 3-phosphate; PI(4)P, phosphatidylinositol 4-phosphate; PI(5)P, phosphatidylinositol 5-phosphate; S1P, sphingosine 1-phosphate; PI(3,4)P₂, phosphatidylinositol 3,4-bisphosphate; PI(3,5)P₂, phosphatidylinositol 3,5-bisphosphate; PI(4,5)P₂, phosphatidylinositol 4,5-bisphosphate; PI(3,4,5)P₃, phosphatidylinositol 3,4,5-triphosphate; PA, phosphatidic acid; PS, phosphatidylserine. Error bars, S.D. a.u., arbitrary units.