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Quantifying Positional Isomers (QPI) by top-down mass spectrometry

ABSTRACT: Proteomics has exposed a plethora of post-translational modifications, but demonstrating functional relevance requires new approaches. Top-down proteomics can characterize co-occurring modifications in terms of localization, abundance and hierarchy. Here, we present a top-down MS analysis workflow for the discovery and quantification of proteoforms. Confident fragment assignment allows for localization of modification sites and quantification of all proteoforms, including positional isomers, as validated by investigating synthetic isoforms of ubiquitin and hyper-phosphorylated Bora.

INSTRUMENT(S): LTQ Orbitrap Elite

ORGANISM(S): Homo Sapiens (human)

SUBMITTER: Richard Scheltema

LAB HEAD: Richard Scheltema

PROVIDER: PXD012084 | Pride | 2021-03-18

REPOSITORIES: Pride

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Quantifying Positional Isomers (QPI) by Top-Down Mass Spectrometry.

Brunner Andrea M AM Lössl Philip P Geurink Paul P PP Ovaa Huib H Albanese P P Altelaar A F Maarten AFM Heck Albert J R AJR Scheltema Richard A RA

Molecular & cellular proteomics : MCP 20210310

Proteomics has exposed a plethora of posttranslational modifications, but demonstrating functional relevance requires new approaches. Top-down proteomics of intact proteins has the potential to fully characterize protein modifications in terms of amount, site(s), and the order in which they are deposited on the protein; information that so far has been elusive to extract by shotgun proteomics. Data acquisition and analysis of intact multimodified proteins have however been a major challenge, in ...[more]

PMID: 33711480

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