F-19-NMR STUDIES OF RETINOL TRANSFER BETWEEN CELLULAR RETINOL-BINDINGPROTEINS AND PHOSPHOLIPID-VESICLES

The cellular retinol binding proteins, CRBP and CRBP II, are implicate d in the cellular uptake of retinol and intracellular trafficking of r etinol between sites of metabolic processing. F-19-NMR studies of reti nol transfer between CRBP and CRBP II and phospholipid vesicles, using either fluorine-labeled ligand or protein, demonstrated that there wa s significantly more transfer of retinol from CRBP II to lipid vesicle s than from CRBP. Differences in how readily protein-bound retinol is released to lipid bilayers may lead to differences in how these two pr oteins modulate intracellular retinol metabolism.