The inactivity of brain phospholipid transfer protein toward phosphatidylinositol 4-phosphate.
Bovine brain phosphatidylinositol transfer protein catalyzes the transport of phosphatidylinositol and, to a lesser extent, phosphatidylcholine between model phospholipid membranes. To investigate the transport of phosphorylated phosphatidylinositol derivatives, 32P-labeled lipids were isolated from guinea pig brain, separated by chromatography on a column of neomycin-coated glass beads, and incorporated into single bilayer vesicles. Under conditions where significant transfer of phosphatidylinositol was observed, no protein-catalyzed transport of phosphatidylinositol 4-phosphate was detected. Thus, the substrate specificity of the brain phospholipid transfer protein cannot be extended to phosphatidylinositol 4-phosphate.
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002352:Carrier Proteins / Q000502:physiology*; D002417:Cattle; D008051:Lipid Bilayers / Q000378:metabolism; D008565:Membrane Proteins; D010716:Phosphatidylinositols / Q000378:metabolism*; D049294:Phospholipid Transfer Proteins
D002352:Carrier Proteins; D008051:Lipid Bilayers; D008565:Membrane Proteins; D010716:Phosphatidylinositols; D049294:Phospholipid Transfer Proteins