Synthesis and properties of radioiodinated phospholipid analogues that spontaneously undergo vesicle-vesicle and vesicle-cell transfer.
An efficient method for the synthesis and purification of a variety of iodinated phospholipid analogues is described. 1-Acyl-2-[[[3-(3-[125I]iodo-4-hydroxyphenyl)- propionyl]amino]caproyl]phosphatidylcholine (125I-PC) was prepared by alkylation of 1-acyl-2-(aminocaproyl)phosphatidylcholine with monoiodinated Bolton-Hunter reagent. 125I-Labeled phosphatidic acid, phosphatidylethanolamine, and phosphatidylserine were produced from 125I-PC by phospholipase D catalyzed base exchange in the presence of ethanol-amine or L-serine. All of these lipid analogues transferred readily from donor vesicles into recipient membranes. When an excess of acceptor vesicles was mixed with a population of donor vesicles containing the iodinated analogues, approximately 50% of the 125I-labeled lipids transferred to the acceptor vesicle population. In addition, under appropriate incubation conditions, these lipids were observed to transfer from vesicles to mammalian cells. Autoradiographic analysis of 125I-labeled lipids extracted from the cells after incubation with vesicles at 2 degrees C for 60 min revealed that a large proportion of the 125I-labeled phosphatidic acid was metabolized to 125I-labeled diglyceride and 125I-labeled phosphatidylcholine, whereas no metabolism of exogenously supplied 125I-labeled phosphatidylethanolamine or 125I-labeled phosphatidylcholine could be detected.
D000818:Animals; D002460:Cell Line; D005354:Fibrosarcoma / Q000378:metabolism; D007202:Indicators and Reagents; D007457:Iodine Radioisotopes; D007553:Isotope Labeling / Q000379:methods; D007700:Kinetics; D008081:Liposomes; D051379:Mice; D010713:Phosphatidylcholines / Q000138:chemical synthesis; D010741:Phospholipases A / Q000378:metabolism; D010743:Phospholipids / Q000138:chemical synthesis* / Q000378:metabolism; D012513:Sarcoma, Experimental / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013329:Structure-Activity Relationship; D010738:Type C Phospholipases / Q000378:metabolism
D007202:Indicators and Reagents; D007457:Iodine Radioisotopes; D008081:Liposomes; D010713:Phosphatidylcholines; D010743:Phospholipids; D010741:Phospholipases A; D010738:Type C Phospholipases