Would you like to become a founder of a new neutron beamline? – Development of a neutron beamline for crystals with giant unit cell dimensions.

 

Topic  46
Main supervisor Tobias Schrader (t.schrader@fz-juelich.de)
MLZ institution FZJ
Local supervisor 1
Ferenc Mezei
Institution Mirrotron
Local supervisor 2
Institution
Local supervisor 3
Institution
Local supervisor 4
Institution
Title
Would you like to become a founder of a new neutron beamline? – Development of a neutron beamline for crystals with giant unit cell dimensions.
Description

The machinery of life relies on proteins acting as catalysts for almost all chemical reactions which are necessary to support the living organism. When proteins adopt this role they are called an enzyme. Neutron protein crystallography has been successfully employed to elucidate the mechanism which these enzymes use in order to fulfil their task. To know the atomistic structure of these enzymes often is the key to understand how they function. X-ray protein crystallography has been used to get structural information on the heavier atoms which sometimes led to a good understanding of the enzymatic mechanism. But neutron protein crystallography can also locate hydrogen atoms which give information on the protonation states of relevant side chains of enzymes in a certain step of their mechanistic action. Especially for large enzymes this is not possible to do with any other method. But often the location of one hydrogen atom gives the missing hint on how the enzyme works.

In order to perform a measurement to locate such a hydrogen atom one needs a crystal of the protein under investigation. This is often not an easy task and crystals usually are as small as 1 mm3. On top of that, they have a large or sometimes giant unit cell size which maybe as large as 200 Å in at least one dimension. This poses challenges to neutron beamlines to accommodate this type of measurements. Among other projects the Jülich High Brilliance Neutron Source is considered a possible future neutron source for Germany. Within this GNEUS project a new instrument for neutron protein crystallography should be designed and simulated based on existing knowledge from other pulsed neutron sources. Thereby, the respective GNEUS candidate will become a founder of a new neutron beamline and will publish papers which will be cited a lot in the future when the beamlime becomes operational. As a secondment an internship at the company Mirrotron in Budapest is planned, a company producing world-class neutron guides which will be an important part of the new beamline. In parallel to the simulation of a new instrument the candidate should get hands on experience on existing neutron diffractometers when applying for beamtime their, which should also lead to a well-cited publication.