Professor Tae-Young Yoon from the Department of Physics has developed a technology to observe the interactions of proteins at the molecular level in real time. His findings were published in the October issue of Nature Protocols as an invited paper.

Professor Yoon and his team first developed a fluorescence microscope with enough resolution to distinguish individual molecules. Making use of the new microscope and co-immunoprecipitation (co-IP) analysis, the team developed a real-time single-molecule co-IP method, and thus was able to observe molecular interactions with a time resolution in the order of tens of milliseconds.

Co-IP analysis is widely used in molecular biology to study protein-protein interactions. However, the process, which makes use of electrophoresis and western blotting, is not optimal for detecting weak and transient interactions that are prevalent in biological systems. Conventional co-IP analysis can take over a day to complete, posing limitations on observing weak and transient interactions, and also making it difficult to obtain real-time data.

Professor Yoon aimed to greatly improve the co-IP analysis method and also provide an avenue for the observation of individual protein-protein interactions. The new process makes it possible to observe protein-protein interactions within an hour, and the entire process – from lysate preparation to kinetic analysis - takes four hours to complete. As a result, real-time observations between two proteins can be made, allowing for even closer inspection of the interactions and the formation of a rich kinetic picture of the target. In addition, all the programs used were developed within Professor Yoon’s lab, thereby securing all the source technology for the new technique.