Enhancing Cysteine Chemoproteomic Coverage through Systematic Assessment of Click Chemistry Product Fragmentation.
Anal Chem
; 94(9): 3800-3810, 2022 03 08.
Article
em En
| MEDLINE
| ID: mdl-35195394
ABSTRACT
Mass spectrometry-based chemoproteomics has enabled functional analysis and small molecule screening at thousands of cysteine residues in parallel. Widely adopted chemoproteomic sample preparation workflows rely on the use of pan cysteine-reactive probes such as iodoacetamide alkyne combined with biotinylation via copper-catalyzed azide-alkyne cycloaddition (CuAAC) or "click chemistry" for cysteine capture. Despite considerable advances in both sample preparation and analytical platforms, current techniques only sample a small fraction of all cysteines encoded in the human proteome. Extending the recently introduced labile mode of the MSFragger search engine, here we report an in-depth analysis of cysteine biotinylation via click chemistry (CBCC) reagent gas-phase fragmentation during MS/MS analysis. We find that CBCC conjugates produce both known and novel diagnostic fragments and peptide remainder ions. Among these species, we identified a candidate signature ion for CBCC peptides, the cyclic oxonium-biotin fragment ion that is generated upon fragmentation of the N(triazole)-C(alkyl) bond. Guided by our empirical comparison of fragmentation patterns of six CBCC reagent combinations, we achieved enhanced coverage of cysteine-labeled peptides. Implementation of labile searches afforded unique PSMs and provides a roadmap for the utility of such searches in enhancing chemoproteomic peptide coverage.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Limite:
Humans
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article