Cholesterol interactions with tetracosenoic acid phospholipids in model cell membranes: role of the double-bond position.
The synthesis and thermotropic properties of 1,2-di-(9Z)-9-tetracosenoylphosphatidylcholine [delta 9-PC(24:1,24:1), 1], 1,2-di-(5Z)-5-tetracosenoylphosphatidylcholine [delta 5-PC(24:1,24:1), 2], and 1,2-di-(15Z)-15- tetracosenoylphosphatidylcholine [delta 15-PC(24:1,24:1), 3] are reported. Liposomes prepared from these phospholipids differ from those of the natural sponge phospholipids, 1,2-di-(5Z,9Z)-5,9-hexacosadienoylphosphatidylcholine (4a) and the corresponding ethanolamine (4b), both of which virtually exclude cholesterol from their bilayers. The behavior of 1 and 2 is similar to that of 1,2-di-(6Z,9Z)-6,9-hexacosadienoylphosphatidylcholine (5), which exhibits a partial molecular interaction with cholesterol. In the case of 3, cholesterol appears to interact with the saturated acyl chain regions of this phospholipid in a manner similar to that of its interaction with DPPC acyl chains. This study delineates the effect of the double-bond location in long fatty acyl chains of phospholipids on their interactions with cholesterol.
Ayanoglu
E
E
Department of Chemistry, Stanford University, California 94305.
Chiche
B H
BH
Beatty
M
M
Djerassi
C
C
Düzgüneş
N
N
D002152:Calorimetry, Differential Scanning; D002462:Cell Membrane / Q000378:metabolism*; D002784:Cholesterol; D005229:Fatty Acids, Monounsaturated; D007202:Indicators and Reagents; D008051:Lipid Bilayers; D008081:Liposomes; D009682:Magnetic Resonance Spectroscopy; D008954:Models, Biological; D010713:Phosphatidylcholines / Q000138:chemical synthesis; D010743:Phospholipids / Q000138:chemical synthesis; D013329:Structure-Activity Relationship
D005229:Fatty Acids, Monounsaturated; D007202:Indicators and Reagents; D008051:Lipid Bilayers; D008081:Liposomes; D010713:Phosphatidylcholines; D010743:Phospholipids; C064583:tetracosenoic acid; D002784:Cholesterol