Comparison of cytidinediphospho-sn-1,2-diglyceride transfer from microsomal and liposomal to mitochondrial membranes.
Transfer of [3H]CDP-diglycerides from isolated guinea pig liver microsomal and liposomal membranes to guinea pig mitochondrial membranes was studied by incubating microsomal or liposomal membranes carrying [3H]CDP-diglycerides with mitochondrial membranes and determining the CDP-diglyceride-dependent incorporation of sn-3-[14C]glycerolphosphate into mitochondrial [14C]polyglycerophosphatides. A significant difference in the amount of transferred [3H]CDP-diglycerides and the composition of mitochondrial [14C]polyglycerophosphatides was found depending on whether [3H]CDP-diglycerides were transferred from microsomal or liposomal membranes. This amount was around 12% when [3H]CDP-diglycerides were transferred from the microsomal membranes and around 4.6% when they were transferred from the liposomal membranes. Furthermore, about 60% of [14C]phosphatidylglycerol and 35% of [14C]phosphatidylglycerophosphate were found in the microsomes-mitochondria system and about 9% of [14C]phosphatidylglycerol and 79% of [14C]phosphatidylglycerophosphate were found in the liposomes-mitochondria system, establishing an important role for the membrane donor in the transfer of [3H]CDP-diglycerides to mitochondria. Furthermore, if the transfer of [3H]CDP-diglycerides from the microsomal to the mitochondrial membranes was assayed by the determination of [3H]CDP-diglycerides in reisolated mitochondrial membranes without further incorporation into mitochondrial polyglycerophosphates, it amounted to about 38%.
Stuhne-Sekalec
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Department of Clinical Biochemistry, Banting Institute, Faculty of Medicine, University of Toronto, Ontario, Canada.
Stanacev
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NZ
D000818:Animals; D001692:Biological Transport; D002850:Chromatography, Gel; D002855:Chromatography, Thin Layer; D003567:Cytidine Diphosphate Diglycerides / Q000378:metabolism*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007425:Intracellular Membranes / Q000378:metabolism*; D008081:Liposomes / Q000378:metabolism*; D008862:Microsomes, Liver / Q000201:enzymology / Q000378:metabolism*; D008930:Mitochondria, Liver / Q000201:enzymology / Q000378:metabolism*; D009702:Nucleoside Diphosphate Sugars / Q000378:metabolism*; D010715:Phosphatidylglycerols / Q000096:biosynthesis
D003567:Cytidine Diphosphate Diglycerides; D008081:Liposomes; D009702:Nucleoside Diphosphate Sugars; D010715:Phosphatidylglycerols; C034358:phosphatidylglycerophosphate