earticle

영어

Understanding of the molecular relationships in carbohydrate-protein interactions provides useful information on biological processes in living organisms and is also helpful for development of potent biomedical agents. To analyze their interaction, first, we modified diverse carbohydrate containing thiol group that was directly immobilized on gold cantilever and electrode. Herein, as the method to characterize interactive formation and binding specificity, we used atomic force microscopy (AFM) and electrochemical detection system. As measuring unbinding force from GM1-Vibrio cholera toxin as well as the analogue analyses, we understood how structural and binding positional differences in complex carbohydrate affect the interaction with protein and surmise that the GM1-ctxAB complex makes a “two-finger grip” formation through the conformational change of a flexible carbohydrate. In addition, we found that a potential shift at the maximum current occurred upon interaction with cholera toxin proteins through electrochemical detection system. By comparing results for different sizes of GM1 analogues, we surmise that the potential shift is closely associated with the specificity for the carbohydrate-protein interaction. In conclusion, using AFM force analysis, we successfully quantified and characterized the interactive configuration of carbohydrate-protein molecules and a carbohydrate-based electrochemical system could be used a tool for specific carbohydrate-protein interaction.