A Magnetic Nanoprobe Technology for Detecting Molecular Interactions in Live Cells.

Technologies to assess the molecular targets of biomolecules inliving cells are lacking. We have developed a technology calledmagnetism-based interaction capture (MAGIC) that identifies moleculartargets on the basis of induced movement of superparamagneticnanoparticles inside living cells. Efficient intracellular uptake ofsuperparamagnetic nanoparticles (coated with a small molecule ofinterest) was mediated by a transducible fusogenic peptide. Thesenanoprobes captured the small molecule's labeled target protein and weretranslocated in a direction specified by the magnetic field. Use ofMAGIC in genome-wide expression screening identified multiple proteintargets of a drug. MAGIC was also used to monitor signal-dependentmodification and multiple interactions of proteins. [ABSTRACT FROM AUTHOR]