Abstract
The complex formation of Ca2+ with a phosphatidylcholine adsorbed at the interface between water and 1, 2-dichloroethane, W|DCE, was evaluated to elucidate the adsorption of ions on biomembrane surfaces. An electrochemical method combined with interfacial tension measurement was adopted for evaluation of the complex formation of the phospholipid and the ion. The association constant for the complex formation of Ca2+ with the lipid was three orders of magnitude higher than those of monovalent cations with the lipid. The present result suggests that the strong complex formation of highly hydrophilic metal cations with a lipid membrane results in a higher affinity to biomembrane surfaces.
