Evidence of Gas Phase Glucosyl Transfer and Glycation in the CID/HCD-Spectra of S-Glucosylated Peptides.

Protein cysteine S-glycosylation is a relatively rare and less well characterized post-translational modification (PTM). Creating reliable model proteins that carry this modification is challenging. The lack of available models or natural S-glycosylated proteins significantly hampers the development of mass-spectrometry-based (MS-based) methodologies for detecting protein cysteine S-glycosylation in real-world proteomic studies.

Protein cysteine S-glycosylation: oxidative hydrolysis of protein S-glycosidic bonds in aqueous alkaline environments.

Some glycoproteins contain carbohydrates S-linked to cysteine (Cys) residues. However, relatively few S-glycosylated proteins have been detected, due to the lack of an effective research methodology. This work outlines a general concept for the detection of S-glycosylation sites in proteins.

Modified cysteine S-phosphopeptide standards for mass spectrometry-based proteomics.

The regulatory role of protein cysteine phosphorylation is an under-researched area. The difficulty of accessing reference S-phosphorylated peptides (pCys-peptides) hampers progress in MS-driven cysteine phosphoproteomics, which requires targeted analytical procedures. This work describes an uncomplicated process for the conversion of disulfide-bridged protein into a complex model mixture of combinatorially modified peptides.