RATIONALE
In spatial proteomics, matrix-assisted laser desorption/ionization (MALDI) imaging enables rapid and cost-effective peptide measurement. Yet, in situ peptide identification remains challenging. Therefore, this study aims to integrate the trapped ion mobility spectrometry (TIMS)-based parallel accumulation-serial fragmentation (PASEF) into MALDI imaging of peptides to enable multiplexed MS/MS imaging.
METHODS
An initial MALDI TIMS MS1 survey measurement is performed, followed by a manual generation of a precursor list containing mass over charge values and ion mobility windows. Inside the dual TIMS system, submitted precursors are trapped, separately eluted by their ion mobility and analyzed in a quadrupole time-of-flight device, thereby enabling multiplexed MALDI MS/MS imaging. Finally, precursors are identified by peptide to spectrum matching.
RESULTS
This study presents the first multiplexed MALDI TIMS MS/MS imaging (iprm-PASEF) of tryptic peptides. Its applicability is showcased on two histomorphologically distinct tissue specimens in a 4-plex and 5-plex setup. Precursors were successfully identified by the search engine MASCOT in one single MALDI imaging experiment for each respective tissue. Peptide identifications were corroborated by liquid-chromatography tandem mass spectrometry experiments and fragment colocalization analyses.
CONCLUSIONS
In the present study, we demonstrate the feasibility of TIMS-based MALDI MS/MS imaging for the multiplexed and rapid identification of tryptic peptides in a spatial manner. Hence, it represents a first step towards the integration of MALDI imaging into the emerging field of spatial proteomics.
The datasets will be uploaded separately. This data set contains the Kidney MSMS data. There is an additional Liver tissue vissible on the .tif image. This was used for another experiment
[doi:10.25345/C5W669M54]
[dataset license: CC0 1.0 Universal (CC0 1.0)]
Keywords: MALDI imaging, MALDI TIMS MSMS imaging, peptide imaging, spatial proteomics, TIMS ; DatasetType:Proteomics
Principal Investigators: (in alphabetical order) |
Prof. Oliver Schilling, Institute for Surgical Pathology, University Medical Center Freiburg, Germany |
Submitting User: | oliver_schilling |
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Owner | Reanalyses | |
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