In vivo crystallization

The occurrence of protein crystals in living cells has been observed for many years, but so far little attention was paid to this phenomenon as it was considered to be an untypical behavior of the cell. In contrast to native in vivo crystals formed of viral capsid or storage proteins, it has recently been shown that in vivo crystals can also be formed from recombinant proteins in Sf9 insect cells. In this case, the cathepsin B protease from trypanosoma brucei was recombinantly overexpressed using the baculovirus-Sf9 system, resulting in the formation of needle-shaped intracellular protein crystals. Using the free electron laser (FELs) at LCLS in Stanford, California in combination with serial femtosecond crystallography (SFX), the first biological structure of in vivo grown protein crystals has been be determined with a resolution of 2.1 Å, demonstrating that those crystals can be used for structural biology. In close collaboration with the group of Prof. Rainer Duden at the University of Lübeck, our research focuses on the cellular mechanisms underlying in vivo crystallization to further understand the basis for this phenomenon and to offer new opportunities in future for difficult protein targets that failed to crystallize in vitro so far.

Contact persons for this project: Dr. Lars Redecke, Marco Klinge