Enhancing Top-Down Analysis Using Chromophore-Assisted Infrared Multiphoton Dissociation from (Phospho)peptides to Protein Assemblies.

Infrared multiphoton dissociation (IRMPD) has been used in mass spectrometry to fragment peptides and proteins, providing fragments mostly similar to collisional activation. Using the 10.6 μm wavelength of a CO laser, IRMPD suffers from the relative low absorption cross-section of peptides and small proteins.

Targeting proline in (phospho)proteomics.

Mass spectrometry-based proteomics experiments typically start with the digestion of proteins using trypsin, chosen because of its high specificity, availability, and ease of use. It has become apparent that the sole use of trypsin may impose certain limits on our ability to grasp the full proteome, missing out particular sites of post-translational modifications, protein segments, or even subsets of proteins. To tackle this problem, alternative proteases have been introduced and shown to lead to an increase in the detectable (phospho)proteome.

Crosstalk between phosphorylation and O-GlcNAcylation: friend or foe.

A wide variety of protein post-translational modifications (PTMs) decorate cellular proteins, regulating their structure, interactions and ultimately their function. The density of co-occurring PTMs on proteins can be very high, where multiple PTMs can positively or negatively influence each other's actions, termed PTM crosstalk. In this review, we highlight recent progress in the area of PTM crosstalk, whereby we focus on crosstalk between protein phosphorylation and O-GlcNAcylation.