Capturing Isomeric Heterogeneity and Structural Dynamics Using Transformative Ion Manipulation Platforms

About This Grant

Project Summary/Abstract Chemical separations are foundational to modern chemistry, yet traditional liquid chromatography-mass spectrometry workflows often fail to detect many isomeric and conformational features of biomolecules critical to metabolism, disease, and drug efficacy. To address these limitations, the Clowers Research Group (CRG) at Washington State University is advancing ion mobility spectrometry and mass spectrometry techniques, leveraging gas-phase ion chemistry and high-resolution separations enabled by Structures for Lossless Ion Manipulations (SLIM). SLIM technology’s extended cyclic separations and controlled gas environments allow for the resolution of isomers and intermediates that conventional methods frequently miss. To quantitatively capture isomeric heterogeneity in complex biological systems, the CRG is implementing tailored multiplexed ion strategies such as Phased Ion Mobility Spectrometry. This technique aligns SLIM separations with ultra-performance liquid chromatography timescales, reducing spectral ambiguity and improving the resolution of co-eluting isomers in diverse ‘omics applications. Complementing these strategies, the group is integrating gas-phase labeling techniques, including hydrogen-deuterium exchange (gHDX) and ozone-induced dissociation. These methods provide dynamic insights into molecular interactions by capturing solvent- accessible regions and chemically selective modifications, enhancing the characterization of isomeric and conformational states. The integration of tandem collision-induced unfolding with SLIM and gHDX adds another layer of analytical depth, enabling the isolation and detailed examination of intermediate protein structures. This approach reveals conformational transitions and solvent-accessible regions during unfolding, helping to quantify molecular stability and refine structural models of biopolymers. By combining SLIM-based separations, multiplexing strategies, and gas-phase labeling workflows, the CRG’s research program is redefining bioanalytical approaches. These innovations aim to enhance the detection of isomeric heterogeneity, reduce analytical errors, and provide new insights into metabolomics, lipidomics, and structural biology in support of public health outcomes. 1