Membrane Protein & Kinetic Crystallography Group @ Göteborg University

The Membrane protein & kinetic crystallography group at Göteborg University is led by Richard Neutze, who joined the Department of Chemistry, Biochemistry & Biophysics in July 2006. Our research activities are primarily concerned with three major activities: overexpression & structural studies of membrane proteins; kinetic crystallography studies of membrane proteins; & time-resolved x-ray diffraction method development ultimately looking towards applications studying membrane proteins.

Our focus on new membrane protein structures began in January 2002, when we established a structural biology initiative focusing on membrane proteins with support from Swegene, a collaborative academic research programme in Sweden's southwest sponsored by the Wallenberg Foundation (SWEGENE platform). This platform created a number of collaborative projects ranging from membrane protein overproduction, characterisation & crystallisation with other groups in both Lund & Göteborg. The most important publication from this collaborative work to date is the x-ray structure of the closed and open conformations of the gated plant plasma membrane aquaporin published in Nature in 2006.

Kinetic crystallography is when kinetic parameters, such as temperature or pH, are used to trap a significant population of a specific reaction intermediate in 3D crystals of macromolecules & x-ray diffraction is then used to determine the structure of the desired intermediate. Thus kinetic crystallography provides a method for visualising in detail the subtle structural rearrangements which are required for proteins to perform their biological function. Published structural results from the group include studies on bacteriorhodopsin, sensory rhodopsin II, photosynthetic reaction centre & elastase.

Difference Fourier electron density map showing the disordering of a key water molecule following the photoisomerisation of a retinal chromophore in bacteriorhodopsin [Edman. et al. Nature 401, 822-826 (1999)].

Finally, closely connected to our work with kinetic crystallography, we have pioneered a number of novel ultrafast X-ray diffraction methodologies. This work has included picosecond X-ray scattering studies at the European Synchrotron Radiation Facility in Grenoble & at the laser plasma X-ray source in Lund, as well as theoretical developments. Our future direction in this area is to apply these novel approaches to study membrane proteins & their reaction intermediates.