Single-Molecule Metal-Induced Energy Transfer (smMIET)

ongoing

The core aim of the project is to develop the technology of Single-Molecule Metal-Induced Energy Transfer (smMIET) for resolving macromolecular structure and dynamics with sub-nanometre spatial resolution and nanosecond temporal resolution. Metal-Induced Energy Transfer or MIET was first developed in our group in 2012 for mapping cellular membranes with nanometre axial resolution. It exploits the effect that a fluorescent molecule, when brought close to a metal surface, can transfer its excited state energy to surface plasmons in the metal, which leads to a strong distance-dependence of its fluorescence lifetime and intensity. This strong lifetime-distance dependence allows for converting a measured fluorescence lifetime into a distance from the metal surface. Combining this concept with single-molecule localization super-resolution microscopy and with fluorescence correlation spectroscopy will resolve three-dimensional structures with nanometre isotropic resolution, and structural dynamics on the nanometre length scale with nanosecond temporal resolution. Among its many applications, the project will develop and apply smMIET for resolving the global structure of macromolecular complexes and its dynamics, the conformational fluctuations of intrinsically disordered proteins, the dynamics of lipid membranes in a leaflet-resolved manner, or the transport of proteins across lipid bilayers. We will establish smMIET as a toolbox for structural and molecular biology that is comparable and complementary in its usefulness and versatility to conventional Förster Resonance Energy Transfer (FRET) or Fluorescence Correlation Spectroscopy (FCS).