Investigation of allosteric mechanisms by time-resolved serial synchrotron crystallography

• Applicant: Pedram Mehrabi, Ph.D.
• Subject Area: Structural Biology ; Biophysics
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 451079909

In the course of this scholarship, I would like to develop new methods for the three-dimensional structure determination of proteins, especially with regard to time-resolved X-ray crystallography. One of these methods is the use of high pressure sound waves, the frequency of which is far above the human hearing threshold. These high-pressure sound waves let the sensitive protein crystals float in the X-ray beam and thus enable completely contactless sample transfer. The overarching goal of this development is to simplify data acquisition for time-resolved measurements so that it is also accessible to non-specialized groups. With the current tools, that I co-developed for time-resolved measurements, I will delve into the molecular mechanisms that regulate allostery. In general, allostery is a process in which different areas of an enzyme communicate with each other, through both the enzyme itself and the complex network of water molecules that encompass it. To this end I will primarily focus on the enzyme Fluoroacetate dehalogenase, which is capable of breaking one of the strongest molecular bonds known in chemistry. This will inevitably provide insights into the fundamental nature of how simple molecular machines, such as enzymes function and self regulate. In addition, I plan to carry out introductory time-resolved measurements on Hepatitis C Virus Protease NS3. The NS3 protease is not only an important model system to understand allostery but the protein also has implications in avenues of medicine and health. If the detailed mechanism of this protein can be outlined, I anticipate that better drugs can be developed which have the benefit of staving off resistance. My long-term research aim is pushing the boundaries of the currently available technology for time-resolved crystallography, while uncovering the dynamic characteristics of proteins in broad timescales. These aims also have large implications for the fundamental understanding of enzymes in other avenues of research such as medicine and drug discovery.

• DFG Programme: Independent Junior Research Groups