Protein identification by 3D OrbiSIMS to facilitate in situ imaging and depth profiling.
Abstract
Label-free protein characterization at surfaces is commonly achieved using digestion and/or matrix application prior to mass spectrometry. We report the assignment of undigested proteins at surfaces in situ using secondary ion mass spectrometry (SIMS). Ballistic fragmentation of proteins induced by a gas cluster ion beam (GCIB) leads to peptide cleavage producing fragments for subsequent OrbitrapTM analysis. In this work we annotate 16 example proteins (up to 272 kDa) by de novo peptide sequencing and illustrate the advantages of this approach by characterizing a protein monolayer biochip and the depth distribution of proteins in human skin.
Keywords
Omics
OrbiSIMS
SIMS
MeSH terms
Argon
Humans
Molecular Imaging
Peptide Fragments
Proteins
Proteomics
Skin
Spectrometry, Mass, Secondary Ion
Workflow
Authors
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