Enhancement of the transfer of alpha-tocopherol between liposomes and mitochondria by rat-liver protein(s).
alpha-Tocopherol transfer from liposomes to mitochondria was enhanced by a cytosolic protein in rat liver. This protein was separated from the exchange protein specific for phosphatidylcholine. The stimulation was specific for alpha-tocopherol and the "affinity" order of tocopherols for the cytosolic protein was found to be as follows: alpha-tocopherol greater than gamma-tocopherol much greater than alpha-tocopheryl acetate, alpha-tocopherol quinone. The transfer-stimulating protein may act as a carrier, since an intermediate (alpha-tocopherol)-protein complex could be detected when liposomes containing alpha-tocopherol were incubated with the cytosol. This transfer-stimulating activity was present not only in liver, but also in heart, spleen and lung.
D000818:Animals; D001692:Biological Transport; D003600:Cytosol / Q000378:metabolism; D007700:Kinetics; D008081:Liposomes; D008099:Liver / Q000378:metabolism; D008297:Male; D008930:Mitochondria, Liver / Q000378:metabolism*; D010713:Phosphatidylcholines; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D013329:Structure-Activity Relationship; D014810:Vitamin E / Q000378:metabolism*; D014811:Vitamin E Deficiency / Q000378:metabolism
D008081:Liposomes; D010713:Phosphatidylcholines; D011506:Proteins; D014810:Vitamin E