Computational methods for the structure determination of highly dynamic molecular machines by cryo-EM
von Felix Lambrecht
Datum der mündl. Prüfung:2019-02-16
Erschienen:2019-02-20
Betreuer:Prof. Dr. Holger Stark
Gutachter:Prof. Dr. Helmut Grubmüller
Gutachter:Dr. Michael Habeck
Gutachter:Prof. Dr. Kai Tittmann
Gutachter:Dr. Sarah Adio
Dateien
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Zusammenfassung
Englisch
In the last couple of years, electron cryomicroscopy (cryo-EM) has gained of rising importance in the field of structural biology and biophysics. Not only that the routinely achievable resolution of the method has dramatically increased to routinely near-atomic resolution. First and foremost the opportunity to resolve structures which where far beyond the size limit for classical methods such as X-ray crystallography and NMR increased the popularity. These features make cryo-EM also more and more interesting for the pharmaceutical industry. However, certain challenges are being unresolved until today. One of them is the usage of the full dynamical information cryo-EM experiments bring with them. The other is the fact that classical transmission electron microscopy (TEM) on biological samples still is limited by the radiation sensitivity and the low signal in the images. This thesis will first present a new algorithm based on statistical methods to decipher the conformational landscape of a macromolecular complex from cryo-EM experiments. This information can be used to quantify biochemical phenomena like allostery on the intramolecular level. Such analyses will be discussed to be useful in the drug development pipeline and help to understand the physical foundations of the regulation and function of macromolecular complexes. Secondly, a new imaging method based on scanning TEM will be introduced. In the corresponding publication we evaluate this method in its capability to resolve non-biological samples as well as biological macromolecues. We show that the surrounding medium influences the imaging process in a way that no compromise between the applied dose and the achievable signal can be found and it will be discussed what implications can be drawn for new biological imaging modes in general.
Keywords: cryo-EM; Biophysics; iDPC; Energy Landscapes; Conformational Dynamics