Molecular Biophysics

(Jörn Dietz, Anna Riedl, Dr. Marian Vache)

Single Molecule Analysis

In our research group, we design single-molecule experiments either based on rational design or by using macromolecules provided by nature itself. Stochastic modeling of bond breakage under external load allows for the reconstruction of the energy landscape. Particularly, we use optical tweezers and atomic force microscopy-based loading of individual bonds/molecules (e.g., unfolding of of LHC II (with Harald Paulsen), detachment of synaptotagmin-1 (with Reinhard Jahn) and vimentin (with Sarah Koester).


Along these lines, we employ the consecutive rupture of antibodies attached to the tip of the cantilever and antigen-presenting membrane proteins during the scanning of a cell surface to obtain a high-resolution map of proteins without using fluorescent labels.


Models for Molecular Interactions

We use atomic force microscopy and optical tweezers combined with colloidal probes as a high spatial and temporal resolution displacement and force sensor for direct force evaluation, characterization of mechanical properties or manipulation of biological materials. These particular methods are used to study nanostructure dynamics and interaction processes within ranges of nano- to femto- Newton forces and below millisecond resolution (e.g., nucleocytoplasmic transport).