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

ABSTRACT: 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 particular for positional isomers that carry the same number of modifications at different sites. Solutions were previously proposed to extract this information from fragmentation spectra, but these have so far mainly been limited to peptides and have entailed a large degree of manual interpretation

SUBMITTER: Brunner AM 

PROVIDER: S-EPMC8099777 | biostudies-literature | 2021

REPOSITORIES: biostudies-literature