TY - JOUR AU - Li, Mujia Jenny AU - Meyer, Larissa Chiara AU - Meier, Nadine AU - Witte, Jannik AU - Maldacker, Maximilian AU - Seredynska, Adrianna AU - Schueler, Julia AU - Schilling, Oliver AU - Föll, Melanie Christine TI - Spatial Proteomics by Parallel Accumulation-Serial Fragmentation Supported MALDI MS/MS Imaging: A First Glance Into Multiplexed and Spatial Peptide Identification. JO - Rapid communications in mass spectrometry VL - 39 IS - 9 SN - 0951-4198 CY - New York, NY PB - Wiley Interscience M1 - DKFZ-2025-00301 SP - e10006 PY - 2025 AB - In spatial proteomics, matrix-assisted laser desorption/ionization (MALDI) imaging enables rapid and cost-effective peptide measurements. 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 tryptic peptides to enable multiplexed MS/MS imaging.An initial MALDI TIMS MS1 survey measurement was 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 were 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 were identified by peptide to spectrum matching.This study presents the first multiplexed MALDI TIMS MS/MS imaging (iprm-PASEF) of tryptic peptides. Its applicability was showcased on two histomorphologically distinct tissue specimens in a four-plex and five-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.In this study, we present a novel pipeline, based on iprm-PASEF, that allows the multiplexed and spatial identification of tryptic peptides in MALDI imaging. Hence, it marks a first step towards the integration of MALDI imaging into the emerging field of spatial proteomics. KW - Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization: methods KW - Proteomics: methods KW - Tandem Mass Spectrometry: methods KW - Animals KW - Peptides: chemistry KW - Peptides: analysis KW - Ion Mobility Spectrometry: methods KW - Peptide Fragments: analysis KW - Peptide Fragments: chemistry KW - MALDI imaging (Other) KW - MS/MS imaging (Other) KW - TIMS (Other) KW - iprm‐PASEF (Other) KW - peptide imaging (Other) KW - spatial proteomics (Other) KW - Peptides (NLM Chemicals) KW - Peptide Fragments (NLM Chemicals) LB - PUB:(DE-HGF)16 C6 - pmid:39910729 DO - DOI:10.1002/rcm.10006 UR - https://inrepo02.dkfz.de/record/298584 ER -