A Flexible, Modular Platform for Multidimensional Ion Mobility of Native-like Ions

Area of Science:

• Biophysical techniques
• Mass spectrometry
• Structural biology

Background:

• Native ion mobility (IM) mass spectrometry (MS) is crucial for analyzing biomolecular complex size, shape, and assembly.
• Multidimensional IM-MS (IM-IM-MS) enhances structural studies by enabling isolation of specific structural subpopulations.
• Previous IM-IM-MS implementations utilized the Structures for Lossless Ion Manipulations (SLIM) architecture for gas-phase protein ion stability.

Purpose of the Study:

• To characterize a novel multidimensional IM instrument constructed from modular SLIM devices.
• To evaluate its performance across multiple operational modes for ion manipulation and analysis.
• To demonstrate its flexibility and utility in studying protein structures and dynamics.

Main Methods:

• Characterization of a new multidimensional IM instrument built using modular SLIM devices.
• Single-dimension IM experiments to determine collision cross section (Ω) values for native-like ions.
• Tandem IM experiments on ubiquitin ions to isolate structural subpopulations.
• Demonstration of multiplexed IM and inverse IM modes.

Main Results:

• Collision cross section (Ω) values obtained were within 3% of previously reported measurements.
• Successful isolation of compact and partially unfolded ubiquitin ion structures was achieved.
• The platform demonstrated proficiency in single-dimension, tandem, multiplexed, and inverse IM analyses.

Conclusions:

• The new multidimensional IM instrument, built from SLIM devices, is a highly flexible platform for structural and dynamic studies of proteins.
• Its modular design allows for rapid switching between various IM analysis modes.
• This instrument advances the capabilities of IM-MS for detailed biomolecular structural investigations.