MALDImID: Spatialomics R package and Shiny app for more specific identification of MALDI imaging proteolytic peaks

Cristiano Oliveira1, Rémi Longuespée2

  • 1Faculty of Biosciences, University of Heidelberg, Heidelberg, Germany.

Proteomics
|April 12, 2023
PubMed

Insights

Matrix-assisted laser desorption/ionization (MALDI) imaging aids protein localization in formalin-fixed paraffin-embedded (FFPE) tissues. An R package and Shiny app improve protein identification by integrating liquid chromatography-tandem mass spectrometry data with MALDI imaging.

Area of Science:

  • Proteomics
  • Molecular Pathology
  • Biotechnology

Background:

  • Matrix-assisted laser desorption/ionization (MALDI) imaging is valuable for protein localization in formalin-fixed paraffin-embedded (FFPE) tissues.
  • Protein identification using traditional MALDI-time-of-flight (TOF) and post-source decay (PSD) fragmentation is often challenging and time-consuming.

Purpose of the Study:

  • To develop a method for more specific identification of peaks in bottom-up MALDI imaging data.
  • To leverage liquid chromatography-tandem mass spectrometry (LC-MS/MS) proteomic data for enhanced MALDI imaging analysis.

Main Methods:

  • Implementation of an R package for data analysis.
  • Development of a Shiny application for user-friendly access to the analytical tools.
  • Integration of LC-MS/MS proteomic biomarker discovery data with MALDI imaging datasets.

Main Results:

  • The developed R package and Shiny app facilitate the specific identification of MALDI imaging peaks.
  • The approach enhances the utility of MALDI imaging in molecular pathology by improving protein identification accuracy.
  • The Shiny app provides direct access to the implemented tool for researchers.

Conclusions:

  • The new R package and Shiny app significantly improve protein identification in MALDI imaging of FFPE tissues.
  • This integration bridges the gap between proteomic biomarker discovery and spatial proteomics.
  • The tools enhance the application of MALDI imaging in tissue classification and molecular pathology workflows.