title: The protein-mediated net transfer of phosphatidylinositol in model systems.
abstract: The phospholipid monolayer technique has been used to study the transfer activity of the phospholipid exchange protein from beef brain. In measuring the transfer between a monolayer consisting of equimolar amounts of phosphatidylcholine and phosphatidylinositol and liposomes consisting of 98 mol% phosphatidylcholine and 2 mol% phosphatidylinositol, the beef brain protein demonstrates an 8-fold higher transfer activity for phosphatidylinositol than for phosphatidylcholine. Under similar conditions the phosphatidylcholine exchange protein from beef liver showed a great preference for phosphatidylcholine. Phosphatidylcholine liposomes devoid of phosphatidylinositol still functioned as receptors of phosphatidylinositol when the beef brain exchange protein was present. This indicates that this protein can catalyse a net transfer of phosphatidylinopsitol. Binding of both phosphatidylinositol and phosphatidylcholine to the beef brain protein was shown.
mesh_terms: D000818:Animals; D001692:Biological Transport; D001921:Brain / Q000378:metabolism*; D002417:Cattle; D008567:Membranes, Artificial; D008954:Models, Biological; D009419:Nerve Tissue Proteins / Q000302:isolation & purification; D010713:Phosphatidylcholines; D010716:Phosphatidylinositols / Q000378:metabolism*; D011485:Protein Binding
chemical_list: D008567:Membranes, Artificial; D009419:Nerve Tissue Proteins; D010713:Phosphatidylcholines; D010716:Phosphatidylinositols