Mapping the Path to Cryogenic Atom Probe Tomography Analysis of Biomolecules

Area of Science:

• Biochemistry
• Biophysics
• Materials Science

Background:

• Understanding protein structure and interactions is vital in biology.
• Existing methods like X-ray crystallography provide averaged views and lack compositional detail.
• Atom probe tomography (APT) shows potential for biomolecular analysis but requires further exploration in native, hydrated states.

Purpose of the Study:

• To explore the capabilities of APT for analyzing biomolecules in frozen aqueous solutions.
• To establish guidelines for cryogenic APT analysis of biomolecules.
• To evaluate critical factors for successful biomolecular analysis using APT.

Main Methods:

• Systematic analysis of amino acids in frozen aqueous solutions.
• Utilized two different nanoporous metal supports.
• Employed a complete cryogenic workflow: drop-casting, glovebox freezing, cryo-transfer, focused ion beam microscopy, and atom probe analysis.
• Used water molecular ion ratios to indicate electrostatic field conditions.

Main Results:

• Investigated amino acid fragmentation and behavior under various conditions.
• Evaluated the impact of support material, cryogenic preparation, and data acquisition parameters.
• Demonstrated the feasibility of analyzing biomolecules in a near-native state using cryogenic APT.

Conclusions:

• Developed guidelines for cryogenic APT analysis of biomolecules.
• Advanced the application of APT in biological sciences for detailed compositional analysis.
• Highlighted the importance of optimized cryogenic workflows and support materials for biomolecular studies.