Neutron protein crystallography: New developments and recent application examples

Schrader, Tobias Erich; Richter, Dieter; Monkenbusch, Michael; Petry, Winfried; Ostermann; Jüttner, Ph.; Laatsch, Bernhard

Poster (Outreach)

FZJ-2018-03710

Neutron protein crystallography: New developments and recent application examples

Schrader, T. E. (Corresponding author)FZJ* ; Ostermann ; Monkenbusch, M.FZJ* ; Laatsch, B.FZJ* ; Jüttner, P. ; Petry, W. ; Richter, D.FZJ*

2017

Instruct Biennial Structural Biology Conference 2017, Brno, Czech Republic, 24 May 2017 - 26 May 2017

Please use a persistent id in citations: http://hdl.handle.net/2128/19199

Abstract: With the advent of new instruments (e. g. Imagine at HFIR, MANDI at SNS and BIODIFF at FRMII) and well established instruments (iBIX at JPARC and LADI at ILL) neutron protein crystallography has seen a resurrection from the past pioneering work by Schoenborn. New sample environment options at the instruments and a growing user community have greatly enhanced the outcome of the existing neutron diffractometers. Measurements at 100 K in a nitrogen gas stream (cryostream) are now routinely possible at most neutron diffractometers. Efforts to increase the flux at the sample position and to reduce the background at the detector enable to measure smaller and smaller protein crystals. Yet, measuring crystals with volumes below 0.1 mm3 is still a big challenge and usually works only in exceptional cases. The main scientific questions addressed are: Hydrogen bonding to ligands/substrates, protonation states of amino acids in intermediate states of the catalytic process and determining the correct structure of metallo-proteins which are subjected to reduction due to the radiation damage caused by x-rays. But also the water shell on the outer surface of the protein can be studied, whereby water molecules of different flexibility can be observed.As an example for a neutron diffractometer, the instrument BIODIFF is introduced: It is a joint project of the Jülich Centre for Neutron Science (JCNS) and the FRM II. BIODIFF is designed as a monochromatic instrument with a narrow wavelength spread of less than 3 %. To cover a large solid angle the main detector of BIODIFF consists of a neutron imaging plate in a cylindrical geometry with online read-out capability. An optical CCD-camera pointing at the sample position is used to quickly align the sample (or a Cadmium replica of it) with respect to the neutron beam. The main advantage of BIODIFF is the possibility to adapt the wavelength to the size of the unit cell of the sample crystal while operating with a clean monochromatic beam that keeps the background level low.In this contribution, a review of most recent application examples of neutron protein crystallography is given. New developments are discussed which may lead to a widening of the application scope of this method. Especially the need for large protein (typically > 0.5 mm3 in volume) crystals is addressed.

Keyword(s): Health and Life (1st) ; Biology (2nd)

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