Fluorescent fatty acid transfer from bovine serum albumin to phospholipid vesicles: collision or diffusion mediated uptake.

Purpose: The extent of palmitate uptake by hepatocytes is dependent upon the surface charge of the extracellular binding protein. Specifically, hepatocyte uptake is greater when palmitate is bound to cationic binding proteins than when it is bound to anionic proteins. To further understand the role of protein surface charge on the uptake process of protein-bound ligands, we examined the rate of transfer of fluorescent anthroyloxy palmitic acid (AOPA) in the presence of anionic and cationic extracellular proteins to model membranes containing different surface charged groups.