symport on planar bilayer lipid membranes (BLMs) and liposomes loaded with the fluorescent pH-sensitive probe 8-hydroxypyrene-1,3,6-trisulfonic acid. The protonophoric action of TFMP-urea proceeded via translocation of neutral protonated form and anionic deprotonated form through the membrane. The presence of palmitic acid in the lipid mixture led to a several-fold increase in the BLM current mediated by TFMP-urea and an improvement in its proton selectivity. We also showed that bovine serum albumin reduced the BLM current mediated by TFMP-urea due to its ability to bind this compound.
Rokitskaya et al. (Mon,) studied this question.