Functionalized lipid bilayer vesicles on which molecular recognition by an artificial receptor synchronized with catalytic reaction by an enzyme were prepared in aqueous media. The system was constructed with the following molecular components: an alkyl amine as a receptor, a pyridoxal derivative as a signal ligand to the receptor, lactate dehydrogenase as an enzyme, Cu^2＋ ions as a mediator between the receptor and the enzyme, and a synthetic peptide lipid as a membrane-forming amphiphile. The design of the present supramolecular assembly was inspired by biological signal transduction system on the cell membrane. Molecular recognition behavior of the signal ligand by the receptor was well correlated with the hydrophobic parameter of the receptor molecules. Marked signal specificity through electrostatic interactions between the signal and the membrane surface was also observed. Strong binding of the mediator species toward the signal-receptor complex in 1∶2 stoichiometry was clarified. As a result, the enzymatic activity on the membrane surface was effectively controlled through molecular recognition by a hydrophobic alkyl amine as the receptor toward pyridoxal 5'-phosphate as the signal ligand.

Key words: intermolecular communication, molecular recognition, lipid bilayer vesicle, receptor, enzyme