The effect of amine structure on complexation with lasalocid in model membrane systems. II. Ionophore selectivity for amines in lipid bilayers and at oil/water interfaces.

ABSTRACT

The ionophore antibiotic X-537A (lasalocid) transports biogenic amines across biological and artificial membranes. The major portion of amine flux (greater than 99%) occurs as a 11 neutral complex. The rank order of ionophore selectivity was determined for lipid bilayer membrane transport of amines based on a comparison of permeability coefficients p-tyramine approximately beta-phenylethylamine approximately amphetamine greater than methamphetamine greater than dopamine greater than phenylephrine approximately metanephrine greater than norepinephrine greater than epinephrine. This rank order is in agreement with results obtained from partitioning measurements which were carried out in parallel to the bilayer membrane experiments. A correlation between amine structure and binding characteristics has been developed.