Methods

Overview of different biochemical and biophysical methods used by the group to study metallo-, radical and redox proteins.

  • Cloning, protein expression and protein purification. 
  • Protein crystallography (PX) – a method that gives the structure of proteins.
  • UV-Vis spectroscopy – gives information about the state of the redox site and chromophores.
  • Raman spectroscopy – gives information about bond vibrations of key active site bonds e.g. Fe-O bonds, -S-S- bonds, H-bonds or tyrosyl-radicals, and indirectly the oxidation state.  
  • Electron Paramagnetic Resonance (EPR) – gives information about nature of radicals, metal-ions/clusters, the spin state and coordinated metal-ion ligands
  • Biological Small Angle X-ray Scattering (BioSAXS) – a low resolution method that gives the shape of proteins, e.g. protein-protein interaction and protein-protein complexes
  • QM/MM and DFT calculations – can give very detailed structural information and can eluidate structure of reactive models and protonation states.
  • Magnetic Circular Dichroism (MCD) – gives information about the coordination around the mono- or di-metal active site and oxidation state
  • Mössbauer Spectroscopy – gives information about the spin state of the metal site.
  • Nuclear Vibrational Resonance Spectroscopy (NVRS) also called vibrational Mössbauer Spectroscopy – a method that gives information about the bond vibration of bonds containing e.g. iron. This is observed as a side effect when a wavelength that set the nucleus into resonance is used.
  • X-ray Absortion Spectroscopy (XAS) and pre edge XAS – a method that give information of oxidation states of e.g. iron and copper, coordination of metal-ions, that can be combined with protein crystals
  • Extended X-ray Absorption Fine Structure Spectroscopy (EXAFS) – a method that gives detailed structural information of the metal based active site.

The figure shows how protein crystallography are combined with single-crystal UV-Vis and Raman spectroscopy.