Liposomal glyco-microarray for studying glycolipid-protein interactions.

A microarray enables high-throughput interaction screening of numerous biomolecules; however, fabrication of a microarray composed of cellular membrane components has proven difficult. We report fabrication of a liposomal glyco-microarray by using an azide-reactive liposome that carries synthetic and natural glycolipids via chemically selective and biocompatible liposome immobilization chemistry. Briefly, liposomes carrying anchor lipid dipalmitoylphosphatidylethanolamine (DPPE)-PEG(2000)-triphenylphosphine and ganglioside (GM1 or GM3) were prepared first and were then printed onto an azide-modified glass slide so as to afford a liposomal glyco-microarray via Staudinger ligation. Fluorescent dye release kinetics and fluorescence imaging confirmed successful liposome immobilization and specific protein binding to the intact arrayed glycoliposomes. The liposomal glyco-microarray with different gangliosides showed their specific lectin and toxin binding with different binding affinity. The azide-reactive liposome provides a facile strategy for fabrication of either a natural or a synthetic glycolipid-based membrane-mimetic glycoarray. This liposomal glyco-microarray is simple and broadly applicable and thus will find important biomedical applications, such as studying glycolipid-protein interactions and toxin screening applications.