Correlated matrix-assisted laser desorption/ionization mass spectrometry and fluorescent imaging of photocleavable peptide-coded random bead-arrays

Rapid Commun Mass Spectrom. 2014 Jan 15;28(1):49-62. doi: 10.1002/rcm.6754.

Abstract

Rationale: Rapidly performing global proteomic screens is an important goal in the post-genomic era. Correlated matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and fluorescent imaging of photocleavable peptide-coded random bead-arrays was evaluated as a critical step in a new method for proteomic screening that combines many of the advantages of MS with fluorescence-based microarrays.

Methods: Small peptide-coded model bead libraries containing up to 20 different bead species were constructed by attaching peptides to 30-34 µm diameter glass, agarose or TentaGel® beads using photocleavable biotin or a custom-designed photocleavable linker. The peptide-coded bead libraries were randomly arrayed into custom gold-coated micro-well plates with 45 µm diameter wells and subjected to fluorescence and MALDI mass spectrometric imaging (MALDI-MSI).

Results: Photocleavable mass-tags from individual beads in these libraries were spatially localized as ~65 µm spots using MALDI-MSI with high sensitivity and mass resolution. Fluorescently tagged beads were identified and correlated with their matching photocleavable mass-tags by comparing the fluorescence and MALDI-MS images of the same bead-array. Post-translational modification of the peptide Kemptide was also detected on individual beads in a photocleavable peptide-coded bead-array by MALDI-MSI alone, after exposure of the beads to protein kinase A (PKA).

Conclusions: Correlated MALDI-MS and fluorescent imaging of photocleavable peptide-coded random bead-arrays can provide a basis for performing global proteomic screening.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Microarray Analysis / instrumentation
  • Microarray Analysis / methods
  • Microspheres*
  • Models, Molecular
  • Peptide Library
  • Peptides / chemistry*
  • Peptides / metabolism
  • Phosphorylation
  • Photolysis*
  • Sensitivity and Specificity
  • Spectrometry, Fluorescence / methods*
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods*
  • Streptavidin

Substances

  • Peptide Library
  • Peptides
  • Streptavidin