title: Facilitated transfer of cholesteryl ester between rough and smooth microsomal membranes by plasma lipid transfer protein.
abstract: The accessibility of intracellular membrane cholesteryl esters to removal was tested with plasma lipid transfer protein as a tool. Incubation of a mixture of non-radioactive smooth microsomes + rough microsomes prelabeled with cholesteryl ester resulted in slight movement (2-4%) of radioactive cholesteryl ester into smooth microsomes. With the addition of increasing amounts of plasma lipid transfer protein to the mixture, the % transfer of cholesteryl ester into smooth microsomes progressively increased until a plateau was reached at 14%. Movement of cholesteryl ester in the reverse direction was examined with non-radioactive rough microsomes as an acceptor and smooth microsomes prelabeled with cholesteryl ester as a donor. The pattern of the % cholesteryl ester transferred in the reverse and forward direction was almost identical in the presence of plasma lipid transfer protein, showing bidirectional movement of cholesteryl ester between membranes.
mesh_terms: D000818:Animals; D001692:Biological Transport; D002352:Carrier Proteins / Q000502:physiology*; D002788:Cholesterol Esters / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D007425:Intracellular Membranes / Q000378:metabolism*; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D002352:Carrier Proteins; D002788:Cholesterol Esters; C030363:lipid transfer protein