PubMed1995
The solute retention mechanism on immobilized artificial membranes (IAMs) was studied using three different IAM.PC phases. IAMs were prepared by immobilizing either single-chain or double-chain phosphatidylcholine (PC) ligands. Solute affinity for the single-chain IAM.PC columns (with a ligand density of 127 mumol of PC/g of IAM) was 3-fold lower compared to solute affinity on the double-chain IAM.PC column (with a ligand density of 98 mumol of PC/g of IAM). This suggests that the solute retention on IAMs is dominated by a solute partitioning mechanism. Temperature-dependent studies indicated that the thermodynamics of solute partitioning is similar on both the single-chain and double-chain IAM.PC surfaces. For a set of phenol derivatives, the partitioning into IAM.PC surfaces is both enthalpy and entropy driven. For beta-blockers, the partitioning into IAM.PC surfaces is entropy driven. The free energy of solute partitioning into IAMs correlates very well with the free energy of solute partitioning into liposomes.