Capability of arsonolipids to transport divalent cations: a Pressman cell study

The ability of the newly synthesized arsonolipids (2,3-diacyloxypropylarsonic acids) to transport cations was studied using the Pressman cell. Experimental results demonstrate that arsonolipids are much more efficient carriers of Ca2+ and Mg2+ than natural phosphatidic acid in the Pressman cell experiments. The ability of arsonolipids to transfer Ca2+ is affected by the lipid side chain length in the order: C-12 much greater than C-14 congruent to C-16. Ca2+ is transferred faster than Mg2+, suggesting that the latter is more tightly bound to the arsonolipids. The transfer kinetic curves are parabolic for C-12, while initially linear with a tendency to reach a steady state for C-14 and C-16, when the pH in the donor compartment was 8.3. The transport kinetics for both ions studied were best fitted by an equation derived from saturation kinetics that apply in reversible chemical reactions. The ion transfer rates increased as the pH in the donor compartment decreased. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.