The purpose of the proposed project is to explore and develop the chemistry of new amphipathic host molecules at model membrane surfaces. Central to this goal is the synthesis of amphipathic cyclodextrins and the examination of their properties (host-guest complexation, catalysis, and aggregation) in the presence of membrane vesicles. These results will serve to delineate the principles that govern molecular recognition at membrane surfaces with particular emphasis on the contributions of hydrophobic binding, electrostatic attraction and repulsion, and hydrogen bonding. These investigations will serve to elucidate the chemical mechanisms that underly biological recognition processes, which play a decisive role in the "social behavior" of cells. Thus, the results of this work will bear upon the problems of cell-cell fusion, metabolic regulation, carcinogenesis, immunology, and drug-delivery. The second phase of this research will involve the synthesis of more complicated amphipathic hosts with designed functions: transmembrane information transfer, information storage, transmembrane induced catalysis, and molecular sensing.