Differential transfer of C and E apolipoproteins from very-low-density lipoprotein to lysophosphatidylcholine-phosphatidylcholine micelles.
Rat plasma VLDL was incubated with lysoPC/PC micelles consisting of 45-90 mol% lysoPC at micelle/VLDL phospholipid ratios of 0.33-6. Following incubation, the VLDL and micellar particles were reisolated by ultracentrifugation and the lipid and apolipoprotein composition determined by high-temperature gas chromatography and polyacrylamide gel electrophoresis, respectively. Lysophosphatidylcholine was found to equilibrate between the very-low-density lipoproteins and micellar fraction without transfer of phosphatidylcholine or sphingomyelin between these fractions. This produced reisolated VLDL and micellar particles with nearly identical lysoPC/PC ratios. Only apolipoprotein E transferred to reisolated micellar fractions with less than 35 mol% lysoPC. The C apolipoproteins were also transferred to the micellar fraction when the reisolated micelles contained more than 35 mol% lysoPC. It is concluded that apolipoproteins E and C can bind to HDL-size micellar particles of appropriate composition. The differential transfer of apolipoproteins E and C indicates that fundamental differences exist between these apolipoproteins in their interaction with lipid interfaces.
D000818:Animals; D001053:Apolipoproteins / Q000097:blood* / Q000302:isolation & purification; D001054:Apolipoproteins A; D001056:Apolipoproteins C; D003102:Colloids; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D008079:Lipoproteins, VLDL / Q000097:blood*; D008244:Lysophosphatidylcholines; D008297:Male; D008823:Micelles; D008854:Microscopy, Electron; D008970:Molecular Weight; D010713:Phosphatidylcholines; D051381:Rats; D011919:Rats, Inbred Strains; D013109:Sphingomyelins
D001053:Apolipoproteins; D001054:Apolipoproteins A; D001056:Apolipoproteins C; D003102:Colloids; D008079:Lipoproteins, VLDL; D008244:Lysophosphatidylcholines; D008823:Micelles; D010713:Phosphatidylcholines; D013109:Sphingomyelins