Dynamic nuclear polarisation of biological matter

Area of Science:

• Biophysics
• Materials Science
• High Energy Physics

Background:

• Polarized targets are crucial for high-energy physics and biological structure research using polarized neutrons.
• Achieving significant nuclear polarization in biological targets has been a persistent challenge.
• Existing frozen spin target materials offer high polarization but are not optimized for biological applications.

Purpose of the Study:

• To develop and characterize a polarized frozen spin target suitable for biological structure research.
• To overcome the limitations of achieving reasonable nuclear polarization in biological samples.
• To enable advanced studies of biological structures using polarized neutron techniques.

Main Methods:

• Preparation of a polarized frozen spin target from lysozyme enzyme in a deuterated matrix.
• Doping the target with a deuterated paramagnetic radical.
• Utilizing 4 mm microwave irradiation in a 2.5 tesla magnetic field at 0.3 K.

Main Results:

• Successfully polarized clusters of 700 protons within the lysozyme structure to 75%.
• Achieved high polarization levels within one hour of irradiation.
• Demonstrated polarization behavior comparable to the best frozen spin target materials used in high-energy physics.

Conclusions:

• The developed polarized frozen spin target is effective for biological applications.
• This technique significantly advances the potential of polarized neutron research in structural biology.
• The method provides a new avenue for investigating biological structures at a molecular level.