Pulsed EPR Methods to Study Biomolecular Interactions
Irina Ritsch,
Daniel Klose,
Henrik Hintz,
Adelheid Godt,
Gunnar Jeschke,
Maxim Yulikov
Affiliations
Irina Ritsch
Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, CH-8093 Zurich, SCS-Metrohm Award for best oral presentation in Physical Chemistry;, Email: [email protected]
Daniel Klose
Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, CH-8093 Zurich
Henrik Hintz
Faculty of Chemistry and Center for Molecular Materials (CM2), Bielefeld University, Universitätsstrasse 25, D33615 Bielefeld
Adelheid Godt
Faculty of Chemistry and Center for Molecular Materials (CM2), Bielefeld University, Universitätsstrasse 25, D33615 Bielefeld
Gunnar Jeschke
Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, CH-8093 Zurich
Maxim Yulikov
Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, CH-8093 Zurich
Orthogonal site-directed spin labelling in combination with pulsed EPR spectroscopy is a powerful approach to study biomolecular interactions on a molecular level. Following a surge in pulse EPR method development, it is now possible to access distance distributions in the nanometre range in systems of complex composition. In this article we briefly outline the necessary considerations for measurements of distance distributions in macromolecular systems labelled with two or more different types of paramagnetic centres. We illustrate the approach with two examples: an application of the Double Electron-Electron Resonance (DEER) method on a triple spin-labelled protein dimer labelled with nitroxide and Gd(III), and an optimisation study of the Relaxation Induced Dipolar Modulation Enhancement (RIDME) experiment for the orthogonal spin pair Cu(II)-nitroxide.
