Themed collection Ion Mobility Mass Spectrometry

Welcome to this Analyst themed issue on ion mobility mass spectrometry, guest edited by Perdita Barran and Brandon Ruotolo.

There is an ever increasing need to develop new tools to aid in the diagnosis and monitoring of human diseases.

Enabling IM-MS instrumentation and techniques for characterizing sample structural heterogeneity have developed rapidly over the last five years.

Ion mobility-mass spectrometry (IM-MS) is often employed to look at the secondary, tertiary, and quaternary structures of naked peptides and proteins in the gas-phase.

EM∩IM enables the calculation of collision cross-sections from electron density maps obtained, for example, by means of transmission electron microscopy. This capability will further aid the integration of ion mobility mass spectrometry with modern structural biology.

We report collision cross sections (CCS) of high-mannose N-glycans as [M + Na]⁺, [M + K]⁺, [M + H]⁺, [M + Cl]⁻, [M + H₂PO₄]⁻ and [M − H]⁻ ions, measured by drift tube (DT) ion mobility-mass spectrometry (IM-MS) in helium and nitrogen gases.

Computational methods are employed to study the protomers in ESI-IM-MS.

Top-down, multidimensional mass spectrometry for the molecular level characterization of polymer–peptide or polymer–protein conjugates that cannot be crystallized or chromatographically purified.

Native and ion-mobility mass spectrometry reveal the conformational evolution over time of a peptide deformylase binding different ligands, which is consistent with slow-tight inhibition of the enzyme.

Mass spectrometry shows insulin oligomers [I]_n where n ranges from 1-12, and ion mobility analysis reveals ∼60 structurally distinct species across this oligomer distribution. Experimental data trains MD simulations to characterize a persistent prefibrillar protein oligomer that is a dimer enriched in β sheets.

Surface collisions generate subcomplexes, which are then separated by ion mobility and dissociated into their individual subunits via a second stage of surface collisions to elucidate protein complex architecture and assembly.

Linked scans of the differential ion mobility spectrometry carrier gas and compensation field yield resolving powers >7900, more than 16 times greater than the best previously reported values.

Multiprotein complexes have been shown to play critical roles across a wide range of cellular functions, but most probes of protein quaternary structure are limited in their ability to analyze complex mixtures and polydisperse structures using small amounts of total protein.

Separation and identification of isomeric species is a major challenge in lipidomics. Herein, we demonstrate that lipid isomers that differ only in position of the acyl chain, position of the double bond or double bond geometry can be distinguished using drift-tube ion mobility-mass spectrometry, even in complex biological samples.

Mobility Selected Ion Manipulations into Orthogonal Channels.

Fragmentation of melezitose by IMS-CID-IMS-MS.

A new two-phased approach to combining raw frequency encoded data enables enhanced levels of signal to noise ratio for ion mobility mass spectrometry experiments.

This paper reports on the use of divalent metal ion adduction, gas-phase electron transfer reactions, and ion mobility spectrometry to discriminate among isomeric oligosaccharides.

Existing instrumental resolving power limitations in ion mobility spectrometry (IMS) often restrict adequate characterization of unresolved or co-eluting chemical isomers.

LESA mass spectrometry coupled with high field asymmetric waveform ion mobility spectrometry (FAIMS) for the analysis of dried blood spots.

The precise molecular mechanisms by which different peptides and proteins assemble into highly ordered amyloid deposits remain elusive.

Drift gas selection in an ion mobility-QTOF can affect the separation of targeted isomeric compounds and collision cross section values.

3D surface mapping of the IM-MS instrument performance allows the maximum resolving power to be accessed for any ion system.

The local collision probability approximation (LCPA) method is introduced to compute molecular momentum transfer cross sections for comparison to ion mobility experiments.

Understanding the mechanisms and energetics of ion solvation using differential mobility spectrometry.

Introduction of a novel negative mode calibrant and evaluation of calibration strategies for TWIM CCS determination.

Novel μFAIMS/IMS-MS three dimensional separations were optimized to enhance separation power and selectivity in biological analyses.

Evaluation of N_2(g) and He_(g) MOBCAL collision cross section values from 20 compounds ∼ m/z 122 to 609.

We apply a new hyphenated method, TRESI-IMS-MS, to compare equilibrium and kinetic unfolding intermediates of cytochrome c.

We validate the utility of ion mobility to measure protein conformational changes induced by the binding of glycosaminoglycan ligands.

The present work employs trapped ion mobility spectrometry (TIMS) for the analysis of ubiquitin ions known to display a multitude of previously unresolved interchangeable conformations upon electrospray ionization.

The factors affecting conformational preference of gas phase peptide ions are investigated by IM-MS and molecular dynamics simulation.

Adsorption models are used to explain vapor dopant facilitated mobility shifts for peptide ions.