Home Research Labs Chen Lab Chen Lab Protein/peptide modification

Protein/peptide modification

N-glycosylation: We have discovered and engineered the Fbs1 protein, which is involved in glycoprotein quality control in the endoplasmic reticulum (ER), to efficiently enrich intact N-glycopeptides. This technique enables the simultaneous detection of N-glycan composition and peptide sequences, significantly improving the coverage of N-glycosylation mapping.

 

Workflow and graph showing N-glycopeptide enrichment and quantification from HCT116 and DKO1 cells.

 

O-glycosylation: O-glycoproteases (OGPs) are essential tools for O-glycosylation analysis, as they recognize O-glycosylation sites and cleave proteolytically around them. When used in combination with other site-specific proteases (e.g., trypsin), OGP digestion of O-glycoproteins generates short peptides that retain their attached O-glycans. These peptides can then be analyzed by LC-MS/MS to determine both peptide sequences and O-glycan compositions. We are interested in discovering and characterizing novel OGPs with diverse substrate specificities to enable comprehensive and efficient mapping of the highly diverse O-glycosylations.

 

Workflow showing O-glycopeptide generation and identification using proteases and LC-MS/MS analysis.

 

Peptide acetylation: Our lab is also interested in enzymes involved in peptide deacetylation, which may have important applications in peptide sequencing. We employ metagenomic screening and microdroplet-based engineering to pursue such enzymes.