Benchmark Test and Guidelines for DEER/PELDOR Experiments on Nitroxide-Labeled Biomolecules.

Area of Science:

• Structural Biology
• Biophysics
• Spectroscopy

Background:

• Pulsed dipolar EPR spectroscopy yields distance distribution information crucial for structural biology.
• This data is increasingly vital for integrative structural modeling, constraining conformational ensembles.

Purpose of the Study:

• To define quality standards for sample preparation, measurements, data conversion, interpretation, and reporting in pulsed dipolar EPR.
• To enhance the reliability of structural models and biological conclusions derived from EPR data.

Main Methods:

• A multi-laboratory benchmark study was conducted.
• Analysis of datasets with known distance distribution ground truth.
• Focus on proteins labeled with nitroxides and double electron-electron resonance (DEER) measurements.

Main Results:

• Established comprehensive guidelines for pulsed dipolar EPR data acquisition and analysis.
• Validated guidelines through a benchmark study, ensuring data integrity.
• Provided a framework for reliable distance distribution determination.

Conclusions:

• Adherence to these quality standards will improve the accuracy and reproducibility of structural biology studies using pulsed dipolar EPR.
• The guidelines facilitate robust integrative structural modeling and reliable biological interpretations.
• Suggestions are provided for adapting these standards to other experimental systems.