Dynamically polarized samples for neutron protein crystallography at the Spallation Neutron Source

6th European Conference on Neutron Scattering

Zhao, Jinkui^1 ; Pierce, Josh^1 ; Myles, Dean^2 ; Robertson, J.L.^1 ; Herwig, Kenneth W.^1 ; Standaert, Bob^3 ; Cuneo, Matt^2 ; Li, Le^2 ; Meilleur, Flora^2

Instrument and Source Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge

TN

37831, United States^1

Biology and Soft Matter Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge

TN

37831, United States^2

Biosciences Division, Oak Ridge National Laboratory, Oak Ridge

TN

37831, United States^3

关键词: Diffraction backgrounds;    Dynamic nuclear polarization;    Incoherent background;    Neutron protein crystallography;    Neutron scattering instruments;    Oak ridge National Laboratory;    Polarized neutron diffraction;    Spallation neutron sources;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/746/1/012008/pdf
DOI  :  10.1088/1742-6596/746/1/012008

来源: IOP

【 摘 要 】

To prepare for the next generation neutron scattering instruments for the planned second target station at the Spallation Neutron Source (SNS) and to broaden the scientific impact of neutron protein crystallography at the Oak Ridge National Laboratory, we have recently ramped up our efforts to develop a dynamically polarized target for neutron protein crystallography at the SNS. Proteins contain a large amount of hydrogen which contributes to incoherent diffraction background and limits the sensitivity of neutron protein crystallography. This incoherent background can be suppressed by using polarized neutron diffraction, which in the same time also improves the coherent diffraction signal. Our plan is to develop a custom Dynamic Nuclear Polarization (DNP) setup tailored to neutron protein diffraction instruments. Protein crystals will be polarized at a magnetic field of 5 T and temperatures of below 1 K. After the dynamic polarization process, the sample will be brought to a frozen-spin mode in a 0.5 T holding field and at temperatures below 100 mK. In a parallel effort, we are also investigating various ways of incorporating polarization agents needed for DNP, such as site specific spin labels, into protein crystals.