# Gas-Phase Cross-Linking with Ion/Ion Chemistry Coupled to Ion Mobility/Mass Spectrometry

> **NIH NIH R21** · INDIANA UNIVERSITY INDIANAPOLIS · 2020 · $192,953

## Abstract

PROJECT SUMMARY
Although many technologies exist for studying protein structures, none possess a combination of speed,
selectivity, accuracy, resolution, and flexibility. The long-term goal is to use a suite of gas-phase chemistries for
ion/ion reactions coupled to ion mobility (IM) and tandem mass spectrometry (MS) measurements for high-
throughput, virtually sample-prep free, protein structure measurements. The overall objective for this exploratory
project, which is the next step toward attaining our long-term goal, is to implement rapid ion/ion cross-linking
reactions on an IM/MS platform, using tandem mass spectrometry to identify cross-linked sites. The rationale for
the development of this technology is to combine the information from native IM/MS with information obtained
from cross-linking in an experimental method conducted on the sub-second timescale. The increase in
throughput, information, and lack of sample prep (compared to, e.g., X-ray diffractometry, nuclear magnetic
resonance, or cryo-electron microscopy) is expected to advance biomedical research determining protein
structure and function to where protein structural determinations can become rapid and routine. The overall
objective of this application will be reached through the following Specific Aims: 1. Combine gas-phase ion/ion
cross-linking of intact proteins with IM/MS measurements; and 2. Use IM combined with tandem MS to determine
cross-linking locations for intact proteins. For the first aim, a variety of monomeric and multimeric proteins will be
cross-linked in the gas-phase. Changes in overall structure between cross-linked and unmodified proteins, as
well as between solution and gas-phase cross-linked proteins, will be measured by IM. Under the second aim,
a combination of collision induced dissociation (CID) and electron capture dissociation (ECD) will be used to
determine cross-linked sites. The proposed technology is innovative because it represents a substantive
departure from the status quo by coupling cross-linking and native IM/MS analysis into one gas-phase mass
spectrometry experiment, allowing rapid cross-linking analysis and providing multiple complementary measures
of gas-phase protein structure. This new technology is significant because it is expected to become a rapid tool
for high-throughput characterization of primary, secondary, tertiary, and quaternary protein structure. When fully
developed, the technology has the potential to be used for complex mixtures of intact proteins and for rapid
screening of interactions with small molecules/drugs, creating new opportunities in clinical research, treatment,
and drug design.

## Key facts

- **NIH application ID:** 9986846
- **Project number:** 5R21GM134408-02
- **Recipient organization:** INDIANA UNIVERSITY INDIANAPOLIS
- **Principal Investigator:** Ian Webb
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $192,953
- **Award type:** 5
- **Project period:** 2019-08-01 → 2022-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9986846

## Citation

> US National Institutes of Health, RePORTER application 9986846, Gas-Phase Cross-Linking with Ion/Ion Chemistry Coupled to Ion Mobility/Mass Spectrometry (5R21GM134408-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9986846. Licensed CC0.

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