MOLECULAR RECOGNITION AND COLORIMETRIC DETECTION OF CHOLERA-TOXIN BY POLY(DIACETYLENE) LIPOSOMES INCORPORATING G(M1) GANGLIOSIDE

Molecular recognition sites on cell membranes serve as the main commun ication channels between the inside of a cell and its surroundings. Up on receptor binding, celular messages such as ion channel opening or a ctivation of enzymes are triggered. In this report, we demonstrate tha t artificial cell membranes made from conjugated lipid polymers (poly( diacetylene)) can, on a simple level, mimic membrane processes of mole cular recognition and signal transduction. The ganglioside GM1 was inc orporated into poly(diacetylene) liposomes. Molecular recognition of c holera toxin at the interface of the liposome resulted in a change of the membrane color due to conformational changes in the conjugated (en e-yne) polymer backbone. The ''colored liposomes'' might be used as si mple colorimetric sensors for drug screening or as new tools to study membrane-membrane or membrane-receptor interactions.